Method for manufacturing semiconductor device

ABSTRACT

A method for manufacturing a semiconductor device includes: forming a photocatalytic layer and an organic compound layer in contact with the photocatalytic layer over a substrate having a light transmitting property; forming an element forming layer over the substrate having the light transmitting property with the photocatalytic layer and the organic compound layer in contact with the photocatalytic layer interposed therebetween; and separating the element forming layer from the substrate having the light transmitting property after the photocatalytic layer is irradiated with light through the substrate having the light transmitting property.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for manufacturing asemiconductor device having flexibility.

2. Description of the Related Art

It has been required to manufacture semiconductor devices at low cost,and development of elements such as thin film transistors, memories, andsolar cells for control circuits, memory circuits, or the like has beenextensively carried out in recent years (for example, Reference 1:Japanese Published Patent Application No. 2004-47791).

Various applications of semiconductor devices having elements such asthin film transistors, memories, and solar cells are expected, and usingflexible plastic films is attempted in pursuit of reduction in size andweight.

Since plastic films have low heat resistance, it is necessary todecrease the highest temperature in a process. Therefore, a method formanufacturing a semiconductor element is limited. Accordingly, thesemiconductor devices using plastic films are manufactured by anevaporation method or a sputtering method using a metal mask.

A technique is suggested, in which after a polyimide layer is formedover a glass substrate and a layer having a fine element is formed overthe polyimide layer, the polyimide layer is irradiated with a laser beamfrom the glass substrate side, and the polyimide layer and the layerhaving the fine element are separated from the glass substrate to form adisplay device having flexibility (Reference 2: French and others (IanFrench, David McCulloch, Ivar Boerefijin, Nico Kooyman), SID 2005Digest, U.S.A., 2005, pp. 1634-1637)

SUMMARY OF THE INVENTION

However, in the case of manufacturing a semiconductor device by anevaporating method or a sputtering method using a metal mask, a step ofaligning the metal mask is necessary. Therefore, a problem of aligningthe metal mask leads to low yield.

Moreover, in the case of manufacturing a semiconductor device by anevaporation method or a sputtering method using a metal mask, an elementis designed in consideration of the misalignment. Thus, it is difficultto manufacture thin film transistors, memories, and solar cells havingfine structures, or the like, and thus it is difficult to achievereduction in size and weight and improvement in performance ofsemiconductor devices.

In the separation method shown in Reference 2, a laser beam is deliveredfrom a glass substrate side to peel a polyimide layer; however, theenergy of the laser beam is unstable and fluctuates, so that there is aphenomenon that a part of the polyimide layer is not separated from theglass substrate. As a result, there arises a problem in that yield isdecreased. In addition, when the polyimide layer is irradiated with alaser beam having strong energy through the glass substrate so thatyield is improved, there is a problem in that glass and an elementincluded in a layer are damaged.

An object of the present invention is to provide a method formanufacturing a semiconductor device with high yield without damaging alayered product. Further, another object of the present invention is toprovide a method for manufacturing a semiconductor device whose entirethickness is thin and which is light weight and flexible, with highyield.

One feature of the present invention is a method for manufacturing asemiconductor device which includes: forming a photocatalytic layer andan organic compound layer in contact with the photocatalytic layer overa substrate having a light transmitting property; forming an elementforming layer over the substrate having the light transmitting propertywith the photocatalytic layer and the organic compound layer in contactwith the photocatalytic layer interposed therebetween; and separatingthe element forming layer from the substrate having the lighttransmitting property after the photocatalytic layer is irradiated withlight through the substrate having the light transmitting property. Inaddition, separation is performed at an interface between thephotocatalytic layer and the organic compound layer, so that the elementforming layer is separated from the substrate having the lighttransmitting property.

Note that the organic compound layer may be formed over the substratehaving the light transmitting property with the photocatalytic layerinterposed therebetween.

In addition, the photocatalytic layer may be formed over the substratehaving the light transmitting property with an organic compound layerinterposed therebetween.

In addition, a substrate having flexibility may be attached to a surfaceof the organic compound layer after the element forming layer isseparated from the substrate having the light transmitting property.

In addition, the organic compound layer may include an inorganiccompound particle. Further, the organic compound layer may include alight shielding property. In this case, the organic compound layerincludes an optical absorber or a light reflector.

In addition, a wavelength of the light is a wavelength which activatesthe photocatalytic layer.

In addition, the element forming layer includes at least one of a thinfilm transistor, a diode, a resistor, a light emitting element, a liquidcrystal element, and an electrophoresis element.

In addition, the above-described semiconductor device is a semiconductordevice which functions as a light emitting device, a liquid crystaldisplay device, an electrophoretic display device, a wireless chip, asolar cell, or a sensor.

In the present invention, a photocatalytic layer and an organic compoundlayer are formed over a substrate having a light transmitting property,an element forming layer having an element with a fine structure isformed over the photocatalytic layer and the organic compound layer byusing a semiconductor process, and then, the photocatalytic layer isirradiated with light from the substrate having the light transmittingproperty. Accordingly, at an interface between the photocatalytic layerand the organic compound layer, photocatalytic reaction can be generatedand the photocatalytic layer and the organic compound layer can beseparated from each other without using light with high energy.Therefore, a semiconductor device which has flexibility and an elementincluding a fine structure formed by using a conventional semiconductorprocess can be easily manufactured. In addition, a semiconductor devicewhich has flexibility and an element forming layer including an elementwith a fine structure can be manufactured with high yield by using aconventional semiconductor process.

In addition, after a photocatalytic layer, an organic compound layerhaving a light shielding property, and an element forming layer aresequentially formed over a substrate having a light transmittingproperty, the photocatalytic layer is irradiated with light from thesubstrate having the light transmitting property, and the photocatalyticlayer and the organic compound layer having the light shielding propertycan be separated from each other. At this time, light with which thephotocatalytic layer is irradiated can be prevented from entering theelement forming layer; therefore, a characteristic of the element can beprevented from changing due to light, and a semiconductor device whichhas high reliability and flexibility can be manufactured. In addition, asemiconductor device which has flexibility and an element forming layerincluding an element with a fine structure can be manufactured with highyield by using a conventional semiconductor process.

In addition, after a photocatalytic layer, an organic compound layer inwhich inorganic compound particles are dispersed, and an element forminglayer are sequentially formed over a substrate having a lighttransmitting property, the photocatalytic layer is irradiated with lightfrom the substrate having the light transmitting property, and thephotocatalytic layer and the organic compound layer in which theinorganic compound particles are dispersed are separated from eachother. At this time, since the element forming layer is provided withthe organic compound layer in which the inorganic compound particles aredispersed, mechanical strength is increased, and a semiconductor devicecan be prevented from breaking when the semiconductor device is curved.In addition, a semiconductor device which has flexibility and an elementforming layer including an element with a fine structure can bemanufactured with high yield by using a conventional semiconductorprocess.

Further, cohesion between the photocatalytic layer and the organiccompound layer can be lowered by light. Therefore, causes of separationbetween the photocatalytic layer and the organic compound layer can becontrolled, and unintended separation can be prevented. Accordingly, asemiconductor device which has flexibility and an element forming layerincluding an element with a fine structure can be manufactured with highyield by using a conventional semiconductor process.

Since the organic compound layer remaining on one surface of the elementforming layer can be used as a substrate, the number of substrateshaving flexibility can be reduced, and cost of the semiconductor devicecan be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1E are cross sectional views illustrating a manufacturingprocess of a semiconductor device of the present invention.

FIGS. 2A to 2E are cross sectional views illustrating a manufacturingprocess of a semiconductor device of the present invention.

FIGS. 3A to 3E are cross sectional views illustrating a manufacturingprocess of a semiconductor device of the present invention.

FIGS. 4A to 4E are cross sectional views illustrating a manufacturingprocess of a semiconductor device of the present invention.

FIGS. 5A to 5D are cross sectional views illustrating a manufacturingprocess of a semiconductor device of the present invention.

FIGS. 6A to 6D are cross sectional views illustrating a manufacturingprocess of a semiconductor device of the present invention.

FIGS. 7A to 7D are cross sectional views illustrating a manufacturingprocess of a semiconductor device of the present invention.

FIGS. 8A to 8D are cross sectional views illustrating a manufacturingprocess of a semiconductor device of the present invention.

FIGS. 9A to 9D are cross sectional views illustrating a manufacturingprocess of a semiconductor device of the present invention.

FIGS. 10A to 10D are cross sectional views illustrating a manufacturingprocess of a semiconductor device of the present invention.

FIGS. 11A to 11D are cross sectional views illustrating a manufacturingprocess of a semiconductor device of the present invention.

FIGS. 12A to 12D are cross sectional views illustrating a manufacturingprocess of a semiconductor device of the present invention.

FIGS. 13A to 13E are cross sectional views illustrating a structure of amemory element applicable to the present invention.

FIGS. 14A to 14E are cross sectional views illustrating structures oflight emitting elements applicable to the present invention.

FIGS. 15A to 15D are cross sectional views illustrating structures of aphotoelectric conversion element or a diode applicable to the presentinvention.

FIGS. 16A to 16C are cross sectional views illustrating structures ofthin film transistors applicable to the present invention.

FIGS. 17A to 17D are cross sectional views illustrating structures ofelectrophoresis elements applicable to the present invention.

FIGS. 18A and 18B are cross sectional views illustrating a structure ofa semiconductor device of the present invention.

FIGS. 19A and 19B are cross sectional views illustrating a structure ofa backlight applicable to the present invention.

FIGS. 20A and 20B are cross sectional views illustrating a structure ofa backlight applicable to the present invention.

FIGS. 21A to 21C are cross sectional views illustrating a structure of abacklight applicable to the present invention.

FIGS. 22A and 22B are cross sectional views illustrating structures ofbacklights applicable to the present invention.

FIGS. 23A and 23B are cross sectional views illustrating a structure ofa backlight applicable to the present invention.

FIGS. 24A and 24B are cross sectional views illustrating a structure ofa backlight applicable to the present invention.

FIG. 25 is a cross sectional view illustrating a structure of abacklight applicable to the present invention.

FIG. 26 is a cross sectional view illustrating a structure of asemiconductor device of the present invention.

FIG. 27 is a top view illustrating a structure of a semiconductor deviceof the present invention.

FIGS. 28A to 28C are diagrams illustrating structures of semiconductordevices of the present invention.

FIGS. 29A to 29F are diagrams illustrating applications of semiconductordevices of the present invention.

FIG. 30 is a perspective view illustrating an electric apparatus havinga semiconductor device of the present invention.

FIG. 31 is a diagram illustrating an equivalent circuit which isadaptable to a semiconductor device of the present invention.

FIGS. 32A to 32F are perspective views illustrating electric apparatuseseach having a semiconductor device of the present invention.

FIG. 33 is a graph illustrating electric characteristics of asemiconductor device of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiment modes and embodiments will be described withreference to the drawings. The present invention can be carried out inmany different modes. It is easily understood by those skilled in theart that modes and details disclosed herein can be modified in variousways without departing from the spirit and the scope of the presentinvention. It should be noted that the present invention should not beinterpreted as being limited to the description of the embodiment modesand embodiments given below. Note that like portions or portions havinga like function are denoted by the same reference numerals throughdrawings, and therefore, description thereof is omitted.

Embodiment Mode 1

This embodiment mode will describe a method for manufacturing asemiconductor device having flexibility with high yield by separating anelement forming layer from a substrate having a light transmittingproperty, with reference to FIGS. 1A to 1E.

As shown in FIG. 1A, a photocatalytic layer 102 is formed over asubstrate 101 having a light transmitting property, and an organiccompound layer 103 is formed over the photocatalytic layer 102. Next, anelement forming layer 104 is formed over the organic compound layer 103.

As the substrate 101 having the light transmitting property, a glasssubstrate, a quartz substrate, a plastic substrate having heatresistance enough to withstand the process temperature of the process,or the like can be used. Since the above-mentioned substrate 101 havinga light transmitting property is not restricted in size and shape, forexample, a rectangular substrate with a length of 1 m or more on a sidecan be used as the substrate 101 having the light transmitting property.With such a rectangular substrate, productivity can be drasticallyincreased. This is a superior point to a circular silicon substrate.Here, a glass substrate is used as the substrate 101 having the lighttransmitting property. Note that when a plastic substrate is used as thesubstrate 101 having the light transmitting property, an insulatinglayer having a light transmitting property is preferably formed over asurface of the plastic substrate. As the insulating layer, there aresilicon oxide, silicon nitride, silicon oxynitride, aluminum nitride,and the like. When an insulating layer having a light transmittingproperty is formed over the surface of the plastic substrate, when aphotocatalytic layer is formed later and the photocatalytic layer isirradiated with light, the photocatalytic layer is activated, and aninterface between the plastic substrate and the photocatalytic layer canbe prevented from being separated.

Next, the photocatalytic layer 102 is formed over a surface of thesubstrate 101 having the light transmitting property. The photocatalyticlayer 102 is formed of titanium oxide (TiO_(x)), tin oxide (SnO₂),tungsten oxide (WO₃), zinc oxide (ZnO), bismuth oxide (Bi₂O₃), titanate(MTiO₃), tantalate (MTaO₃), niobate (M₄Nb₆O₁₇), (note that every Mindicates a metal element), CdS, ZnS, or the like. As a crystallinestructure of titanium oxide, an anatase type, a rutile type, or amixture of these types can be used. The photocatalytic layer 102 isformed by a sputtering method, a plasma CVD method, an evaporationmethod, a sol-gel method, an electrophoresis method, a spray method, orthe like.

Titanium oxide doped with metal or nitrogen can be used as thephotocatalytic layer 102. As the metal, there are platinum (Pt), copper(Cu), chrome (Cr), silver (Ag), vanadium (V), iron (Fe), cobalt (Ni),zinc (Zn), rhodium (Rh), palladium (Pd), gold (Au), and the like. Whenthe photocatalytic layer 102 is formed using titanium oxide doped withmetal or nitrogen, the photocatalytic layer 102 can be activated byusing not ultraviolet rays, but using visible light, typically sunlight.Here, titanium oxide is used to form the photocatalytic layer 102.

The photocatalytic layer 102 preferably has a thickness greater than orequal to 0.5 nm and less than or equal to 150 nm, more preferablygreater than or equal to 1 nm and less than or equal to 30 nm. When thethickness of the photocatalytic layer 102 is thinner than theabove-mentioned film thickness, the photocatalytic layer 102 is notactivated even when it is irradiated with light. Therefore, even whenthe organic compound layer 103 is formed over the photocatalytic layer102 later, and the photocatalytic layer 102 is irradiated with light,the photocatalytic layer 102 and the organic compound layer 103 aredifficult to be separated from each other at an interface between thephotocatalytic layer 102 and the organic compound layer 103. On theother hand, when the thickness of the photocatalytic layer 102 isthicker than the above-mentioned film thickness, even when thephotocatalytic layer 102 is irradiated with light and activated speciesare generated, the activated species are deactivated before theactivated species move to the interface between the photocatalytic layer102 and the organic compound layer 103; therefore, the photocatalyticlayer 102 and the organic compound layer 103 are difficult to beseparated from each other.

Next, the organic compound layer 103 is formed over photocatalytic layer102. As the organic compound layer 103, an organic compound such as acyanoethyl cellulose resin, polyimide, polyethylene, polypropylene, apolystyrene resin, a silicone resin, an epoxy resin, vinylidenefluoride, or the like can be used. Alternatively, aromatic polyamide orpolybenzimidazole may be used. As a further alternative, a resinmaterial such as a vinyl resin such as polyvinyl alcohol or polyvinylbutyral; a phenol resin; a novolac resin; an acrylic resin; a melamineresin; a urethane resin; or an oxazole resin (polybenzoxazole) may beused. In addition, polyimide, a vinyl acetate resin, polyvinyl acetal,polystyrene, an AS resin, a methacrylic resin, polypropylene,polycarbonate, celluloid, acetyl cellulose plastic, a methylpenteneresin, a vinyl chloride resin, a polyester resin, an urea resin, or thelike may be used, and polyimide is used to form the organic compoundlayer 103 here.

The organic compound layer 103 preferably has a thickness greater thanor equal to 50 nm and less than or equal to 5 μm. When the organiccompound layer 103 is formed to have a thickness greater than or equalto 1 μm and less than or equal to 5 μm, the organic compound layer 103can be used instead of a substrate in the semiconductor device to beformed later. Accordingly, the number of substrates can be reduced andcost reduction is possible.

Next, the element forming layer 104 is formed over the organic compoundlayer 103. As the element forming layer 104, a thin film transistor, athin film transistor having a floating gate electrode, a memory element,a capacitor, a resistor, a diode, or the like may be used. In addition,the element forming layer 104 may have an EL element, a liquid crystalelement, an electron-emissive element, an electrophoresis element, aMEMS (Micro Electro Mechanical System), or the like.

A substrate having flexibility may be provided over a surface of theelement forming layer 104. As the substrate having flexibility,typically, a substrate including PET (polyethylene terephthalate), PEN(polyethylene naphthalate), PES (polyethersulfone), polypropylene,polypropylene sulfide, polycarbonate, polyetherimide, polyphenylenesulfide, polyphenylene oxide, polysulfone, polyphthalamide, or the likecan be used. When any of these substrates is used, the substrate havingflexibility is provided over the element forming layer 104 using anadhesive agent. Moreover, a multilayer film including paper made of afibrous material or a host material film (polyester, polyamide, aninorganic evaporated film, or the like) and an adhesive organic resinfilm (an acrylic-based organic resin, an epoxy-based organic resin, orthe like), or the like can also be used. In the case of using any ofthese multilayer films, when a multilayer film is attached to thesurface of the element forming layer 104 by thermal compression bonding,the adhesive organic resin film is plasticized and functions as anadhesive agent.

Next, as shown in FIG. 1B, the substrate 101 having the lighttransmitting property is irradiated with light 105. As the light 105,light having a wavelength capable of activating the photocatalytic layer102 may be used. Further, a laser beam having a wavelength capable ofactivating the photocatalytic layer 102 may also be used. Typically,when the photocatalytic layer 102 is formed with titanium oxide,ultraviolet rays may be uses as the light 105. When the photocatalyticlayer is formed with CdS, visible light may be used as the light 105.When the photocatalytic layer 102 is irradiated with the light 105through the substrate 101 having the light transmitting property, thephotocatalytic layer 102 is activated. Accordingly, the photocatalyticlayer 102 and the organic compound layer 103 are separated from eachother. Typically, as shown in FIG. 1C, when the photocatalytic layer 102is formed using titanium oxide, oxidizability of titanium oxide isincreased due to the irradiation with the light 105, and acarbon-hydrogen bond of the organic compound layer 103 is broken at theinterface between the photocatalytic layer 102 and the organic compoundlayer 103. Accordingly, a surface of the organic compound layer 103becomes rough, and a part of the organic compound layer 103 becomescarbon dioxide and water and degassing is generated. As a result, theactivate photocatalytic layer 102 and the organic compound layer 103 areseparated from each other.

By the above-described steps, as shown in FIG. 1D, a semiconductordevice including the element forming layer 104 and the organic compoundlayer 103 can be formed. Note that after the separation process shown inFIG. 1C, the surface of the organic compound layer 103 may be providedwith a substrate 106 having flexibility, so that a semiconductor deviceas shown in FIG. 1E may be formed.

When the substrate 106 having flexibility is used, mechanical strengthof the semiconductor device to be formed later can be increased. Inaddition, a contaminant from outside can be prevented from being mixedinto the semiconductor device.

As the substrate 106 having flexibility, a similar one to the substratehaving flexibility which can be provided over the surface of the elementforming layer 104 can be selected as appropriate.

By the above-described process, photocatalytic reaction can be generatedat the interface between the photocatalytic layer and the organiccompound layer, so that the photocatalytic layer and the organiccompound layer can be separated from each other. Therefore, asemiconductor device which has flexibility and an element including afine structure formed by using a conventional semiconductor process canbe easily manufactured.

Embodiment Mode 2

This embodiment mode will describe another mode of a manufacturingprocess of the photocatalytic layer 102 and the organic compound layer103, which is different from Embodiment Mode 1, with reference to FIGS.2A to 2E.

As shown in FIG. 2A, the organic compound layer 103 is formed over thesubstrate 101 having the light transmitting property, and thephotocatalytic layer 102 is formed over the organic compound layer 103.Then, the element forming layer 104 is formed over the photocatalyticlayer 102.

In this embodiment mode, since the photocatalytic layer 102 isirradiated with light through substrate 101 having a light transmittingproperty and the organic compound layer 103, the organic compound layer103 is formed using a material capable of transmitting light which is tobe delivered later. Typically, a material capable of transmitting any ofultraviolet rays, visible rays, or infrared rays is used. As an organiccompound having a light transmitting property, there are polyimide,acrylic, a vinyl acetate resin, polyvinyl acetal, polystyrene, an ASresin, a methacrylic resin, polypropylene, polycarbonate, celluloid,acetyl cellulose plastic, polyethylene, a methylpentene resin, a vinylchloride resin, a polyester resin, an urea resin, and the like.

Next, as shown in FIG. 2B, the photocatalytic layer 102 is irradiatedwith the light 105 through the substrate 101 having the lighttransmitting property and the organic compound layer 103. As a result,the photocatalytic layer 102 is activated. Accordingly, thephotocatalytic layer 102 and the organic compound layer 103 areseparated from each other as shown in FIG. 2C.

By the above-described steps, as shown in FIG. 2D, a semiconductordevice including the element forming layer 104 and the photocatalyticlayer 102 can be formed. Note that after the separation process shown inFIG. 2C, a surface of the photocatalytic layer 102 may be provided withthe substrate 106 having flexibility, so that a semiconductor device asshown in FIG. 2E may be formed.

By the above-described process, photocatalytic reaction can be generatedat the interface between the photocatalytic layer and the organiccompound layer, so that the photocatalytic layer and the organiccompound layer can be separated from each other. Therefore, asemiconductor device which has flexibility and an element including afine structure formed by using a conventional semiconductor process canbe easily manufactured.

Embodiment Mode 3

This embodiment mode will describe a mode in which a semiconductordevice is formed using an organic compound layer 112 in which inorganiccompound particles are dispersed instead of the organic compound layer103 in Embodiment Modes 1 and 2, with reference to FIGS. 3A to 3E. Notethat in this embodiment mode, Embodiment Mode 1 is used for description;however, Embodiment Mode 2 can be applied.

As shown in FIG. 3A, the photocatalytic layer 102 is formed over thesubstrate 101 having the light transmitting property, and the organiccompound layer 112 is formed over the photocatalytic layer 102. Then,the element forming layer 104 is formed over the organic compound layer112. Note that as the organic compound layer 112, inorganic compoundparticles 111 are dispersed in an organic compound 110.

As the inorganic compound particles 111, silicon oxide, siliconenitride, aluminum oxide, tantalum oxide, barium fluoride magnesium, orthe like can be used. When the inorganic compound particles 111 aredispersed in the organic compound layer 103, mechanical strength of anorganic compound layer 114 is increased; therefore, a semiconductordevice to be formed later can be prevented from breaking when thesemiconductor device is curved.

Next, as shown in FIG. 3B, the photocatalytic layer 102 is irradiatedwith the light 105 through the substrate 101 having the lighttransmitting property. As a result, the photocatalytic layer 102 isactivated. Accordingly, as shown in FIG. 3C, the photocatalytic layer102 and the organic compound layer 112 in which the inorganic compoundparticles 111 are dispersed in the organic compound 110 are separatedfrom each other.

By the above-described steps, as shown in FIG. 3D, a semiconductordevice including the element forming layer 104 and the organic compoundlayer 112 in which the inorganic compound particles 111 are dispersed inthe organic compound 110 can be formed. Note that after the separationprocess shown in FIG. 3C, a surface of the organic compound layer 112may be provided with the substrate 106 having flexibility, so that asemiconductor device as shown in FIG. 3E may be formed.

When an organic compound layer in which inorganic compound particles aredispersed is used as the organic compound layer, an element forminglayer which has been separated from a photocatalytic layer can beprovided with the organic compound layer in which the inorganic compoundparticles are dispersed. Therefore, a semiconductor device having highmechanical strength can be manufactured.

Embodiment Mode 4

This embodiment mode will describe a mode in which a semiconductordevice is manufactured using the organic compound layer 114 in whichparticles 113 having light shielding properties are dispersed in theorganic compound 110, instead of the organic compound layer 103 or theorganic compound layer 112 in which the inorganic compound particles 111are dispersed in the organic compound 110 in Embodiment Modes 1 to 4,with reference to FIGS. 4A to 4E. Note that Embodiment Mode 1 is usedfor description in this embodiment mode; however, Embodiment Mode 2 orEmbodiment Mode 3 can be applied.

As shown in FIG. 4A, the photocatalytic layer 102 is formed over thesubstrate 101 having the light transmitting property, and the organiccompound layer 114 is formed over the photocatalytic layer 102. Then,the element forming layer 104 is formed over the organic compound layer114. As the organic compound layer 114, the particles 113 having lightshielding properties are dispersed in the organic compound 110.

Particles (light absorbers) which absorb light in the wavelength rangefrom 280 to 780 nm or particles (light reflectors) which reflect lightare preferably used as the particles 113 having light shieldingproperties. As particles which absorb light, dye or an ultravioletabsorber can be used. As typical examples of dyes, there are anazo-based dye, an anthraquinone-based dye, a naphthoquinone-based dye,an isoindolinone-based dye, a perylene-based dye, an indigo-based dye, afluorenone-based dye, a phenazine-based dye, a phenothiazine-based dye,a polymethine-based dye, a polyene-based dye, a diphenylmethane-baseddye, a triphenylmethane-based dye, a quinacridone-based dye, anacridine-based dye, a phthalocyanine-based dye, and aquinophthalocyanine-based dye, carbon black, and the like. As theultraviolet absorber, there are a benzotriazole-based compound, ahydroxybenzophenone-based compound, a salicylate-based compound, and thelike. As the particles which reflect light, typically, there are anelement selected from titanium (Ti), aluminum (Al), tantalum (Ta),tungsten (W), molybdenum (Mo), copper (Cu), chrome (Cr), neodymium (Nd),iron (Fe), nickel (Ni), cobalt (Co), ruthenium (Ru), rhodium (Rh),palladium (Pd), osmium (Os), iridium (Ir), silver (Ag), gold (Au),platinum (Pt), cadmium (Cd), zinc (Zn), silicon (Si), germanium (Ge),zirconium (Zr), or barium (Ba); particles having a single layer of analloy material, a nitride, an oxide, a carbide, or a halogenatedcompound which includes the above element as a main component; orparticles having a layered structure thereof. The particles 113 havinglight shielding properties may be uniformly dispersed in the organiccompound 110. Alternatively, the particles 113 having light shieldingproperties may be dispersed particularly with high concentration in aregion which is not in contact with the photocatalytic layer 102.

When the particles 111 having light shielding properties are dispersedin the organic compound layer 114, light which has passed without beingabsorbed in the photocatalytic layer 102 can be absorbed in the organiccompound layer 114. Accordingly, the element of the element forminglayer 104 can be prevented from being irradiated with the light 105, anddestruction of an element due to light irradiation can be prevented.

Next, as shown in FIG. 4B, the photocatalytic layer 102 is irradiatedwith the light 105 through the substrate 101 having the lighttransmitting property. As a result, the photocatalytic layer 102 isactivated. Accordingly, the photocatalytic layer 102 and the organiccompound layer 114 including the particles 113 having light shieldingproperties are separated from each other as shown in FIG. 4C.

By the above-described steps, as shown in FIG. 4D, a semiconductordevice including the element forming layer 104 and the organic compoundlayer 114 including the particles 113 having light shielding propertiescan be formed. Note that after the separation process shown in FIG. 4C,a surface of the organic compound layer 114 including the particles 113having light shielding properties may be provided with the substrate 106having flexibility, so that a semiconductor device as shown in FIG. 4Emay be formed.

By the above-described steps, when the photocatalytic layer isirradiated with the light from the substrate having the lighttransmitting property, and the photocatalytic layer and the organiccompound layer having the light shielding property are separated fromeach other, the light with which the photocatalytic layer is irradiatedcan be prevented from entering the element forming layer. Accordingly,it is possible to prevent changes in characteristics of the element dueto the light with which the photocatalytic layer is irradiated, and asemiconductor device which has high reliability and flexibility can bemanufactured.

Embodiment Mode 5

This embodiment mode will describe a typical example of the structure ofthe element forming layer 104 in Embodiment Modes 1 to 4, with referenceto FIGS. 5A to 5D. Note that Embodiment Mode 1 is used for descriptionin this embodiment mode; however, any of Embodiment Modes 2 to 4 can beapplied. In this embodiment mode, a mode having an element 126 in whicha first conductive layer, a functional layer 123, and a secondconductive layer are formed over the element forming layer 104 isdescribed.

Similarly to Embodiment Mode 1, as shown in FIG. 5A, the photocatalyticlayer 102 is formed over the substrate 101 having the light transmittingproperty, and the organic compound layer 103 is formed over thephotocatalytic layer 102. Next, an element forming layer is formed overthe organic compound layer 103.

Next, an insulating layer 120 may be formed over the organic compoundlayer 103. The insulating layer 120 is provided so as to prevent animpurity or gas from the organic compound layer 103, the photocatalyticlayer 102, or the substrate 101 having the light transmitting propertyfrom entering the element forming layer. The insulating layer 120 isformed with a single layer or a layered structure of silicon nitride,silicon oxide, aluminum nitride, or the like.

A first conductive layer 121 is formed over the insulating layer 120.Next, an insulating layer 122 may be formed so as to cover an endportion of the first conductive layer 121. Next, the functional layer123 is formed over the first conductive layer 121, and a secondconductive layer 124 is formed over the functional layer 123. Next, aninsulating layer 125 may be formed over the second conductive layer 124.In addition, a substrate 128 having flexibility may be provided over theinsulating layer 125 with an adhesive agent 127 interposed therebetween.Here, the element 126 can be formed with the first conductive layer 121,the functional layer 123, and the second conductive layer 124.

As for the element 126, there are an EL (Electro Luminescence) elementhaving a light emitting material in the functional layer 123; a memoryelement having the functional layer 123 which is formed using a materialwhose crystalline state, conductivity, shape, or the like is changed dueto voltage application or light irradiation; a diode or a photoelectricconversion element having the functional layer 123 which is formed usinga semiconductor material whose electric characteristic is changed due tolight irradiation; a capacitor having a dielectric layer in thefunctional layer 123; and the like.

The first conductive layer 121 and the second conductive layer 124 canbe formed in a single layer or layered structure by using a metal,alloy, compound, or the like having high conductivity by a sputteringmethod, a plasma CVD method, a coating method, a printing method, anelectrolytic plating method, an electroless plating method, or the like.Typically, a metal, alloy, conductive compound, mixture thereof, or thelike having a high work function (specifically 4.0 eV or higher) can beused. Moreover, a metal, alloy, conductive compound, mixture thereof, orthe like having a low work function (specifically 3.8 eV or lower) canbe used.

As a typical example of a metal, alloy, or conductive compound having ahigh work function (specifically 4.0 eV or higher), indium tin oxide(hereinafter called ITO), indium tin oxide containing silicon, indiumoxide containing 2 to 20 atomic % of zinc oxide (ZnO), or the like isgiven. Moreover, titanium (Ti), gold (Au), platinum (Pt), nickel (Ni),tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co),copper (Cu), palladium (Pd), a nitride of a metal material (such astitanium nitride (TiN), tungsten nitride (WN), or molybdenum nitride(MoN)), or the like can be used.

As a typical example of a metal, alloy, or conductive compound having alow work function (specifically 3.8 eV or lower), a metal belonging toGroup 1 or 2 of the periodic table of the elements, i.e., an alkalimetal such as lithium (Li) or cesium (Cs), an alkaline earth metal suchas magnesium (Mg), calcium (Ca), or strontium (Sr); aluminum (Al); analloy containing any of these (such as MgAg or AlLi); a rare earth metalsuch as europium (Er) or ytterbium (Yb); an alloy containing the rareearth metal; or the like can be used.

Note that when the element 126 is an EL element, a memory element, adiode, or a photoelectric conversion element, the first conductive layer121 or the second conductive layer 124 is formed with a material havinga light transmitting property such as ITO, indium tin oxide containingsilicon, indium oxide containing 2 to 20 atomic % of zinc oxide, orindium oxide-tin oxide containing tungsten oxide and zinc oxide. Inaddition, even when the first conductive layer 121 or the secondconductive layer 124 is formed with a material having low transmittanceof visible light (typically, the above-described alkali metal, alkalineearth metal, aluminum, and an alloy containing any of these), the firstconductive layer 121 or the second conductive layer 124 can have a lighttransmitting property by being deposited with a thickness of about 1 nmto 50 nm, preferably about 5 nm to 20 nm.

The material of the functional layer 123 is selected as appropriate inaccordance with the structure of the element 126.

The insulating layer 122 is provided so as to prevent breaking of thefunctional layer 123 which would otherwise be caused by steps of thefirst conductive layers 121 or to prevent an effect of an electric fieldin a lateral direction between the elements. Note that at the crosssection of the insulating layer 122, a side surface of the insulatinglayer 122 preferably has an angle of inclination with respect to thesurface of the first conductive layer 121, which is greater than orequal to 10° and less than 60°, more preferably greater than or equal to25° and less than or equal to 45°. Furthermore, the upper end portion ofthe insulating layer 122 is preferably curved.

The insulating layer 122 can be formed using an inorganic insulator suchas silicon oxide, silicone nitride, silicon oxynitride, or aluminumnitride by a thin film forming method such as a CVD method or asputtering method. In addition, the insulating layer 122 can be formedusing an organic resin or a high molecular material such as polyimide,polyamide, benzocyclobutene, an acrylic resin, an epoxy resin, or asiloxane polymer, or the like by a coating method, a printing method, anink-jet method, or the like. Furthermore, the insulating layer 122 canbe formed with a single layer or a layered structure using any of theinorganic insulator, the high molecular material, and the organic resin.

The insulating layer 125 functions as a protective film, and can beformed using silicon oxide, silicone nitride, silicon oxynitride, DLC(Diamond Like Carbon), aluminum nitride, or the like by a thin filmforming method such as a CVD method or a sputtering method.

As the adhesive agent 127, an acrylic resin, an epoxy resin, a siliconeresin, or the like can be used.

As the substrate 128 having flexibility, a similar one to the substratehaving flexibility which can be provided over the surface of the elementforming layer 104 shown in Embodiment Mode 1 can be selected asappropriate.

Next, as shown in FIG. 5B, the photocatalytic layer 102 is irradiatedwith the light 105 through the substrate 101 having the lighttransmitting property. As a result, the photocatalytic layer 102 isactivated. Accordingly, the photocatalytic layer 102 and the organiccompound layer 103 are separated from each other as shown in FIG. 5C.

By the above-described steps, as shown in FIG. 5C, a semiconductordevice 129 including the element 126 and the organic compound layer 103can be formed. Note that after the separation process shown in FIG. 5C,the surface of the organic compound layer 103 may be provided with asubstrate 130 having flexibility, so that a semiconductor device 131 asshown in FIG. 5D may be formed.

In addition, as shown in FIG. 6A, a switching element may be connectedto the element 126. As the switching element, there are a thin filmtransistor, MIM (Metal-Insulator-Metal), a diode, and the like. Here, amode in which a thin film transistor 141 is used as the switchingelement is shown.

That is, as shown in FIG. 6A, the photocatalytic layer 102 is formedover the substrate 101 having the light transmitting property, and theorganic compound layer 103 is formed over the photocatalytic layer 102.Next, the thin film transistor 141 which functions as a switchingelement is formed over the organic compound layer 103. Next, a firstconductive layer 142 connected to wirings 1405 of the thin filmtransistor 141 is formed with an insulating layer 140 interposedtherebetween. Note that the wiring of the thin film transistor 141 andthe first conductive layer 142 are connected to each other with theinsulating layer 140 interposed therebetween; however, the presentinvention is not limited to this structure, and the first conductivelayer 142 may be formed with the wiring of the thin film transistor 141.

Here, a structure of the thin film transistor will be described withreference to FIGS. 16A and 16B. FIG. 16A shows an example of a staggeredthin film transistor. The photocatalytic layer 102 and the organiccompound layer 103 are provided over the substrate 101, and the thinfilm transistor 141 is provided over the organic compound layer 103. Asthe thin film transistor 141, a gate electrode 1402 and an insulatinglayer 1403 which serves as a gate insulating film, a semiconductor layer1404 which overlaps with the gate electrode and the insulating layer1403 which serves as a gate insulating film, and the wirings 1405 whichare connected to the semiconductor layer 1404 are provided. Note that apart of the semiconductor layer 1404 is interposed between theinsulating layer 1403 which serves as a gate insulating film and thewirings 1405.

The gate electrode 1402 can be formed by using a similar material andmethod to the first conductive layer 121. In addition, the gateelectrode 1402 can be formed by using a droplet discharging method, andthen drying and baking. Further, the gate electrode 1402 can be formedby printing a paste including fine particles by a printing method overthe organic compound layer 103, and then drying and baking the paste. Astypical examples of the fine particles, fine particles which includes,as a main component, any of gold; copper; an alloy of gold and silver;an alloy of gold and copper; an alloy of silver and copper; or an alloyof gold, silver and copper may be given. Furthermore, the fine particlesmay include a conductive oxide such as ITO as a main component.

The insulating layer 1403 which serves as a gate insulating film can beformed by using a similar material and method to the insulating layer120. The insulating layer 1403 can be formed using the organic compoundlayer shown in the organic compound 110, as appropriate.

As a material for the semiconductor layer 1404 of a thin filmtransistor, a semiconductor material can be used, and an amorphoussemiconductor layer including one or more of silicon and germanium canbe formed by a thin film forming method such as a sputtering method or aCVD method. In addition, by using a material having high heat resistancefor the organic compound layer 103, and irradiating the amorphoussemiconductor layer with a laser beam, a crystalline semiconductor layerwhich is crystallized can be used. Furthermore, an organic semiconductorcan be used for the semiconductor layer 1404.

As the organic semiconductor, a polycyclic aromatic compound, aconjugated double bond compound, phthalocyanine, a charge-transfercomplex, or the like can be given. For example, anthracene, tetracene,pentacene, 6T (hexathiophene), TCNQ (tetracyanoquinodimethane), PTCDA(perylenetetracarboxylic dianhydride), NTCDA (naphthalenetetracarboxylicdianhydride), or the like can be used. As a material of thesemiconductor layer 1404 of the organic semiconductor transistor, aπ-conjugated high molecular material such as an organic high molecularcompound, a carbon nanotube, polyvinyl pyridine, a phthalocyanine metalcomplex, or the like can be given. In particular, polyacetylene,polyaniline, polypyrrole, polythienylene, a polythiophene derivative,poly(3-alkylthiophene), a polyparaphenylene derivative, or apolyparaphenylene vinylene derivative is preferably employed, which is aπ-conjugated high molecular material whose skeleton is formed withconjugated double bonds.

As a method for forming the semiconductor layer 1404 of the organicsemiconductor transistor, a method for forming a film having a uniformthickness may be used. The thickness of the semiconductor layer ispreferably set to be greater than or equal to 1 nm and less than orequal to 1000 nm, and more preferably, greater than or equal to 10 nmand less than or equal to 100 nm. As a specific method, an evaporationmethod, an electron beam evaporation method, a coating method, or thelike can be used.

As shown in FIG. 16B, the gate electrode 1402, the insulating layer 1403which serves as a gate insulating film, the wirings 1405, and thesemiconductor layer 1404 which overlaps with the gate electrode and theinsulating layer which serves as the gate insulating layer may beformed. Further, a part of the wirings 1405 is interposed between theinsulating layer which serves as the gate insulating layer and thesemiconductor layer 1404.

FIG. 16C shows an example of a top gate thin film transistor. Thephotocatalytic layer 102 and the organic compound layer 103 are providedover the substrate 101, and the thin film transistor 141 is providedover the organic compound layer 103. In the thin film transistor 141, asemiconductor layer 1302 and a gate insulating layer 1113 formed with aninorganic insulator are provided over the organic compound layer 103.Over the gate insulating layer 1113, a gate electrode 1304 correspondingto the semiconductor layer 1302 is formed. An insulating layer (notshown) which serves as a protective layer and an inorganic insulatinglayer 1114 which serves as an interlayer insulating layer are formedover the gate electrode 1304. The wirings 1405 connected to source anddrain regions 1310 of the semiconductor layer are formed. Further, aninsulating layer which serves as a protective layer may be formed overthe wirings 1405.

The semiconductor layer 1302 is a layer which is formed using asemiconductor having a crystalline structure. A non-single crystalsemiconductor or a single crystal semiconductor can be used. Inparticular, it is preferable to use a crystalline semiconductor obtainedby irradiating an amorphous silicon film with a laser beam. In the caseof crystallization by laser irradiation, it is possible to conductcrystallization in such a way that a melting zone in which a crystallinesemiconductor that is melted is continuously moved along an irradiationdirection of a laser beam is delivered, wherein the laser beam is acontinuous wave laser beam or an ultrashort pulsed laser beam having ahigh repetition rate of 10 MHz or more and a pulse width of 1 nanosecondor less, preferably 1 to 100 picoseconds. By using such acrystallization method, a crystalline semiconductor having large graindiameter with a crystal grain boundary extending in one direction can beobtained. By making a drift direction of carriers conform to thedirection where the crystal grain boundary extends, the electric fieldeffect mobility in the transistor can be increased. For example, 400cm²/V·sec or more can be achieved.

Note that when the thin film transistor 141 having a crystallinesemiconductor layer is formed, the organic compound layer 103 ispreferably formed using a compound with high heat resistance. As theorganic compound with high heat resistance, there are polyimide,polycarbonate, an epoxy resin, polyester, polyamide-imide, and the like.

The gate electrode 1304 can be formed with a metal or a poly-crystallinesemiconductor to which an impurity having one conductivity type isadded. In the case of using a metal, tungsten (W), molybdenum (Mo),titanium (Ti), tantalum (Ta), aluminum (Al), or the like can be used.Moreover, a metal nitride obtained by nitriding the metal can also beused. Alternatively, a structure in which a first layer including themetal nitride and a second layer including the metal are stacked may beused. In the case of a layered structure, an end portion of the firstlayer may protrude from an end portion of the second layer. By formingthe first layer using the metal nitride, the first layer can be used asa metal barrier. In other words, the first layer can prevent the metalof the second layer from diffusing into the gate insulating layer 1113and the semiconductor layer 1302 below the gate insulating layer 1113.

The thin film transistor formed by combining the semiconductor layer1302, the gate insulating layer 1113, the gate electrode 1304, and thelike can have any structure such as a single drain structure, an LDD(Lightly Doped Drain) structure, or a gate-overlapped drain structure.Here, a thin film transistor having a single drain structure is shown.Moreover, it is also possible to employ a multi-gate structure in whichtransistors to which gate voltage having the same electric potential isapplied are connected in series, or a dual gate structure in which thesemiconductor layer is sandwiched between the upper and lower gateelectrodes.

In this embodiment mode, the inorganic insulating layer 1114 is formedof an inorganic insulator such as silicon oxide or silicon oxynitride.

The wirings 1405 formed over the inorganic insulating layer 1114 can beprovided so as to intersect with a wiring to be formed in the same layeras the gate electrode 1304 and has a multilayer wiring structure. Themultilayer wiring structure can be obtained by forming wirings over aplurality of stacked insulating layers which have a similar function tothe inorganic insulating layer 1114. The wirings 1405 preferably have acombination of a low-resistant material such as aluminum and barriermetal using a refractory metal material such as titanium (Ti) ormolybdenum (Mo). For example, a layered structure including titanium(Ti) and aluminum (Al), a layered structure including molybdenum (Mo)and aluminum (Al), and the like are given.

Next, an insulating layer 143 which covers an end portion of the firstconductive layer 142 of FIG. 6A is formed. Next, a functional layer 144is formed over the first conductive layer 142 and the insulating layer143, and a second conductive layer 145 is formed over the functionallayer 144. The first conductive layer 142, the insulating layer 143, andthe second conductive layer 145 can be formed similarly to the firstconductive layer 121, the insulating layer 122, and the secondconductive layer 124 of FIGS. 5A to 5D, respectively. Next, aninsulating layer may be formed over the second conductive layer 145.Further, a substrate 147 having flexibility may be provided over thesecond conductive layer 145 and the insulating layer 143 with anadhesive agent 146 interposed therebetween. Here, the element 126 can beformed with the first conductive layer 142, the functional layer 123,and the second conductive layer 145.

Next, as shown in FIG. 6B, the photocatalytic layer 102 is irradiatedwith the light 105 through the substrate 101 having the lighttransmitting property. As a result, the photocatalytic layer 102 isactivated. Accordingly, the photocatalytic layer 102 and the organiccompound layer 103 are separated from each other as shown in FIG. 6C.

By the above-described steps, as shown in FIG. 6C, a semiconductordevice 148 including the element forming layer and the organic compoundlayer 103 can be formed. Note that after the separation process shown inFIG. 6C, the surface of the organic compound layer 103 may be providedwith the substrate 130 having flexibility, so that a semiconductordevice 149 as shown in FIG. 6D may be formed.

Here, a structure of the element 126 which can be applied to thisembodiment mode is shown below.

In the case where the element 126 is a memory element, a material whosecrystalline state, conductivity, shape, or the like is changed byapplication of voltage or irradiation with light is used as thefunctional layer 123. Here, a structure of the memory element is shownbelow, with reference to FIGS. 13A to 13E.

As shown in FIG. 13A, a functional layer 123 is formed with a layer 300including an organic compound. The layer 300 including the organiccompound may be provided either in a single-layer structure or a layeredstructure by stacking a plurality of layers formed with differentorganic compounds.

The thickness of the layer 300 including the organic compound ispreferably set so that the electrical resistance of the memory elementchanges by applying voltage to the first conductive layer 121 and thesecond conductive layer 124. The typical thickness of the layerincluding the organic compound ranges from 5 nm to 100 nm, preferablyfrom 10 nm to 60 nm.

The layer 300 including the organic compound can be formed with anorganic compound having a hole-transporting property or an organiccompound having an electron-transporting property.

As the organic compound having the hole-transporting property, forexample, phthalocyanine (abbreviation: H₂Pc), copper phthalocyanine(abbreviation: CuPc), and vanadyl phthalocyanine (VOPc) are given.Besides those, the following are given:4,4′,4″-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA);4,4′,4″-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine(abbreviation: MTDATA); 1,3,5-tris[N,N-di(m-tolyl)amino]benzene(abbreviation: m-MTDAB);N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine(abbreviation: TPD); 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl(abbreviation: NPB);4,4′-bis{N-[4-di(m-tolyl)amino]phenyl-N-phenylamino}biphenyl(abbreviation: DNTPD); 4,4′-bis[N-(4-biphenylyl)-N-phenylamino]biphenyl(abbreviation: BBPB); 4,4′,4″-tri(N-carbazolyl)triphenylamine(abbreviation: TCTA); and the like. However, the present invention isnot limited to these. Among the above-mentioned compounds, aromaticamine compounds typified by TDATA, MTDATA, m-MTDAB, TPD, NPB, DNTPD,BBPB, and TCTA are preferably used as the organic compound because theyeasily generate holes. The substances mentioned here mainly have a holemobility of 10⁻⁶ cm²/Vs or higher.

As the organic compound having the electron-transporting property, thefollowing metal complex having a quinoline skeleton or a benzoquinolineskeleton, or the like can be used: tris(8-quinolinolato)aluminum(abbreviation: Alq₃); tris(4-methyl-8-quinolinolato)aluminum(abbreviation: Almq₃); bis(10-hydroxybenzo[h]-quinolinato)beryllium(abbreviation: BeBq₂);bis(2-methyl-8-quinolinolato)-4-phenylphenolato-aluminum (BAlq); and thelike. Besides those, the following metal complex having an oxazole-basedligand or a thiazole-based ligand, or the like can be used:bis[2-(2-hydroxyphenyl)benzoxazolato]zinc (abbreviation: Zn(BOX)₂);bis[2-(2-hydroxyphenyl)benzothiazolato]zinc (abbreviation: Zn(BTZ)₂);and the like. Furthermore, in addition to the metal complex,2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation:PBD); 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene(abbreviation: OXD-7);3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenylyl)-1,2,4-triazole(abbreviation: TAZ);3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole(abbreviation: p-EtTAZ); bathophenanthroline (abbreviation: BPhen);bathocuproin (abbreviation: BCP); and the like can also be used. Thesubstances mentioned here mainly have an electron mobility of 10⁻⁶cm²/Vs or higher.

As shown in FIG. 13B, the functional layer 123 may be formed with thelayer 300 including the organic compound and an insulating layer 301formed between the first conductive layer 121 and the layer 300including the organic compound.

The insulating layer 301 is a layer for injecting charges of holes orelectrons from the first conductive layer or the second conductive layerto the layer including the organic compound, by a tunnel effect. Theinsulating layer 301 is formed to have the thickness capable ofinjecting charges to the layer 300 including the organic compound by atunnel effect at a predetermined voltage. The typical thickness of theinsulating layer 301 is greater than or equal to 1 nm and less than orequal to 4 nm, preferably greater than or equal to 1 nm and less than orequal to 2 nm. Since the insulating layer 301 is very thin such that thethickness of the insulating layer 301 is greater than or equal to 1 nmand less than or equal to 4 nm, a tunnel effect occurs in the insulatinglayer 301, resulting in the increase in the charge-injecting property tothe layer 300 including the organic compound. Thus, if the insulatinglayer 301 is thicker than 4 nm, the tunnel effect does not occur in theinsulating layer 301 and the electron injection into the layer 300including the organic compound becomes difficult; thus, the voltage tobe applied at the writing into the memory element increases. Moreover,since the insulating layer 301 is very thin such that the thickness ofthe insulating layer 301 is greater than or equal to 1 nm and less thanor equal to 4 nm, throughput improves.

The insulating layer 301 is formed with an inorganic compound or anorganic compound that is stable thermally and chemically.

As typical examples of the inorganic compound that forms the insulatinglayer 301, the following oxides having an insulating property are given:Li₂O, Na₂O, K₂O, Rb₂O, BeO, MgO, CaO, SrO, BaO, Sc₂O₃, ZrO₂, HfO₂, RfO₂,TaO₂, TcO₂, MnO₂, Fe₂O₃, CoO, PdO, Ag₂O, Al₂O₃, Ga₂O₃, Bi₂O₃, and thelike.

As other typical examples of the inorganic compound that forms theinsulating layer 301, the following fluorides having an insulatingproperty are given: LiF, NaF, KF, RbF, CsF, BeF₂, MgF₂, CaF₂, SrF₂,BaF₂, AIF₃, NF₃, SF₆, AgF, MnF₃, and the like. Moreover, the followingchlorides having an insulating property are given: LiCl, NaCl, KCl,BeCl₂, CaCl₂, BaCl₂, AlCl₃, SiCl₄, GeCl₄, SnCl₄, AgCl, ZnCl₂, TiCl₄,TiCl₃, ZrCl₄, FeCl₃, PdCl₂, SbCl₃, SbCl₂, SrCl₂, TlCl₃, CuCl, CuCl₂,MnCl₂, RuCl₂, and the like. The following bromides having an insulatingproperty are given: KBr, CsBr, AgBr, BaBr₂, SiBr₄, LiBr, and the like.Furthermore, the following iodides having an insulating property aregiven: NaI, KI, BaI₂, TlI₃, AgI, TiI₄, CaI₂, SiI₄, CsI, and the like.

As other typical examples of the inorganic compound that forms theinsulating layer 301, the following carbonates having an insulatingproperty are given typically: Li₂CO₃, K₂CO₃, Na₂CO₃, MgCO₃, CaCO₃,SrCO₃, BaCO₃, MnCO₃, FeCO₃, CoCO₃, NiCO₃, CuCO₃, Ag₂CO₃, ZnCO₃, and thelike. In addition, the following sulfates having an insulating propertyare given typically: Li₂SO₄, K₂SO₄, Na₂SO₄, MgSO₄, CaSO₄, SrSO₄, BaSO₄,Ti₂(SO₄)₃, Zr(SO₄)₂, MnSO₄, FeSO₄, Fe₂(SO₄)₃, CoSO₄, CO₂(SO₄)₃, NiSO₄,CuSO₄, Ag₂SO₄, ZnSO₄, Al₂(SO₄)₃, In₂(SO₄)₃, SnSO₄, Sn(SO₄)₂, Sb₂(SO₄)₃,Bi₂(SO₄)₃, and the like. In addition, the following nitrates having aninsulating property are given typically: LiNO₃, KNO₃, NaNO₃, Mg(NO₃)₂,Ca(NO₃)₂, Sr(NO₃)₂, Ba(NO₃)₂, Ti(NO₃)₄, Sr(NO₃)₂, Ba(NO₃)₂, Ti(NO₃)₄,Zr(NO₃)₄, Mn(NO₃)₂, Fe(NO₃)₂, Fe(NO₃)₃, Co(NO₃)₂, Ni(NO₃)₂, Cu(NO₃)₂,AgNO₃, Zn(NO₃)₂, Al(NO₃)₃, In(NO₃)₃, Sn(NO₃)₂, and the like.Furthermore, nitrides having an insulating property, typified by AlN,SiN, and the like are given. The compositions of these inorganiccompounds are not necessarily a strict integer ratio.

If the insulating layer 301 is formed with the inorganic compound, thethickness of the insulating layer is preferably greater than or equal to1 nm and less than or equal to 2 nm. When the insulating layer has athickness of 3 nm or more, the voltage to be applied at the writingincreases.

As typical examples of the organic compound that forms the insulatinglayer 301, polyimide, acrylic, polyamide, benzocyclobutene, polyester, anovolac resin, a melamine resin, a phenol resin, an epoxy resin, asilicon resin, a furan resin, a diallylphthalate resin, and the like aregiven.

The insulating layer 301 can be formed by an evaporation method, anelectron beam evaporation method, a sputtering method, a CVD method, orthe like. Moreover, a spin coating method, a sol-gel method, a printingmethod, a droplet discharging method, or the like can be used.

As shown in FIG. 13C, an insulating layer 302 having depressions andprojections, which is continuous may be used for the functional layer123, instead of the insulating layer 301. Note that, in this case, it ispreferable that the thickness of the insulating layer at the projectionportion be greater than or equal to 1 nm and less than or equal to 4 nm,and that of the insulating layer at the depression portion be greaterthan or equal to 1 nm and less than 2 nm.

As shown in FIG. 13D, discontinuous insulating layers 303 dispersed overthe first conductive layer 121, may be provided instead of theinsulating layers 301 and 302. The discontinuous insulating layers 303may have an island shape, a stripe shape, a net-like shape, or the like.

Moreover, insulating particles may be provided instead of the insulatinglayers 301 to 303. The insulating particles at this time have a grainsize greater than or equal to of 1 nm and less than or equal to 4 nm.

Moreover, the insulating layers 301 to 303 or the insulating particlesmay be provided between the layer 300 including the organic compound andthe second conductive layer 124.

When the insulating layer with a thickness of 4 nm or less, preferably 2nm or less, is provided between the first conductive layer and the layerincluding the organic compound, or between the layer including theorganic compound and the second conductive layer, a tunnel current flowsto the insulating layer. Thus, it is possible to decrease unevenness involtage to be applied and current value at writing into the memoryelement. Moreover, when the insulating layer with a thickness of 4 nm orless, preferably 2 nm or less, is provided between the first conductivelayer and the layer including the organic compound, or between the layerincluding the organic compound and the second conductive layer, acharge-injecting property due to the tunnel effect increases, wherebythe layer including the organic compound can be made thicker. Thus,short-circuiting at an initial state can be prevented. Accordingly, thereliability of the memory device and the semiconductor device can beimproved.

As a different structure from the above-mentioned one, the functionallayer 123 may be formed using the layer 300 including the organiccompound and an element 306 having a rectification which is formedbetween the layer 300 including the organic compound and the firstconductive layer 121 or between the second conductive layer 124 and thelayer 300 including the organic compound (FIG. 13E). As the element 306having a rectification, typically, a Schottky diode, a diode having a PNjunction, a diode having a PIN junction, or a transistor having a gateelectrode and a drain electrode connected to each other is given.Needless to say, a diode having another structure can also be used.Here, a case is shown, in which a PN junction diode includingsemiconductor layers 304 and 305 is provided between the firstconductive layer 121 and the layer 300 including the organic compound.One of the semiconductor layers 304 and 305 is an N-type semiconductorwhile the other is a P-type semiconductor. By providing the elementhaving a rectification in this way, the selectivity of a memory elementcan be improved and operation margin of reading and writing can beimproved.

In the case where the element 126 is an EL element, a light emittingmaterial is used for the functional layer 123. Here, a structure of theEL element is described below, with reference to FIGS. 14A to 14E.

In addition, when a layer (hereinafter referred to as a light emittinglayer 313) which has a light emitting function and is formed using anorganic compound is formed in the functional layer 123, the element 126serves as an organic EL element.

As the organic compound having a light emitting property, for example,the following are given: 9,10-di(2-naphthyl)anthracene (abbreviation:DNA); 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation:t-BuDNA); 4,4′-bis(2,2-diphenylvinyl)biphenyl (abbreviation: DPVBi);coumarin 30; coumarin 6; coumarin 545; coumarin 545T; perylene; rubrene;periflanthene; 2,5,8,11-tetra(tert-butyl)perylene (abbreviation: TBP);9,10-diphenylanthracene (abbreviation: DPA); 5,12-diphenyltetracene;4-(dicyanomethylene)-2-methyl-6-[p-(dimethylamino)styryl]-4H-pyran(abbreviation: DCM1);4-(dicyanomethylene)-2-methyl-6-[2-(julolidin-9-yl)ethenyl]-4H-pyran(abbreviation: DCM2);4-(dicyanomethylene)-2,6-bis[p-(dimethylamino)styryl]-4H-pyran(abbreviation: BisDCM); and the like. Moreover, compounds capable ofemitting phosphorescence such as the following can be given:bis[2-(4′,6′-difluorophenyl)pyridinato-N,C²](picolinato)iridium(abbreviation: FIrpic);bis{2-[3′,5′-bis(trifluoromethyl)phenyl]pydinato-N,C²}(picolinate)iridium(abbreviation: Ir(CF₃ ppy)₂(pic)); tris(2-phenylpyridinato-N,C²)iridium(abbreviation: Ir(ppy)₃);(acetylacetonato)bis(2-phenylpyridinato-N,C²)iridium (abbreviation:Ir(ppy)₂(acac));(acetylacetonato)bis[2-(2′-thienyl)pyridinato-N,C³]iridium(abbreviation: Ir(thp)₂(acac));(acetylacetonato)bis(2-phenylquinolinato-N,C²)iridium (abbreviation:Ir(pq)₂(acac));(acetylacetonato)bis[2-(2′-benzothienyl)pyridinato-N,C³]iridium(abbreviation: Ir(btp)₂(acac)), and the like.

As shown in FIG. 14A, the element 126 which functions as a lightemitting element may be formed by stacking a hole-injecting layer 311formed with a hole-injecting material, a hole-transporting layer 312formed with a hole-transporting material, the light emitting layer 313formed with an organic compound having a light emitting property, anelectron-transporting layer 314 formed with an electron-transportingmaterial, an electron-injecting layer 315 formed with anelectron-injecting material, and the second conductive layer 124, overthe first conductive layer 121.

Here, the hole-transporting material cited in the description of thelayer 300 including the organic compound in FIG. 13A can be used asappropriate as the hole-transporting material.

In addition to the above-mentioned hole-transporting materials, aconductive high-molecular compound which has been chemically doped,polyethylene dioxythiophene (abbreviation: PEDOT) doped with polystyrenesulfonate (abbreviation: PSS), doped polyaniline (abbreviation: PAni),or the like can be used as the hole-injecting material. Moreover, a thinfilm of an inorganic semiconductor such as molybdenum oxide (MoO_(x)),vanadium oxide (VO_(x)), or nickel oxide (NiO_(x)), or an ultrathin filmof an inorganic insulator such as aluminum oxide (Al₂O₃) is alsoeffective.

Here, as the electron-transporting material, the electron-transportingmaterial cited in the description of the layer 300 including the organiccompound shown in FIG. 13A can be used as appropriate.

As the electron-injecting material, in addition to the above-mentionedelectron-transporting materials, an ultrathin film of an insulator isoften used; for example, a halide of an alkali metal such as LiF or CsF,a halide of an alkaline earth metal such as CaF₂, or an oxide of analkali metal such as Li₂O. Moreover, an alkali metal complex such aslithium acetylacetonate (abbreviation: Li(acac)) or8-quinolinolato-lithium (abbreviation: Liq) is also effective. Further,a material in which the above-mentioned electron-transporting materialand a metal having a low work function such as Mg, Li, or Cs are mixedby a co-evaporation method or the like can be used.

As shown in FIG. 14B, the element 126 which functions as a lightemitting element may be formed using the first conductive layer 121, ahole-transporting layer 316 formed with an organic compound and aninorganic compound having an electron-accepting property with respect tothe organic compound, the light emitting layer 313, anelectron-transporting layer 317 formed with an organic compound and aninorganic compound having an electron-donating property with respect tothe organic compound, and the second conductive layer 124.

The hole-transporting layer 316 formed with the organic compound and theinorganic compound having the electron-accepting property with respectto the organic compound is formed by appropriately using theabove-mentioned organic compound having the hole-transporting propertyas the organic compound. As the inorganic compound, any inorganiccompound can be used as long as electrons are easily accepted from theorganic compound, and various metal oxides or metal nitrides can beused. In particular, an oxide of a transition metal belonging to any ofGroups 4 to 12 of the periodic table of the elements is preferablebecause such an oxide is likely to have an electron-accepting property.Specifically, titanium oxide, zirconium oxide, vanadium oxide,molybdenum oxide, tungsten oxide, rhenium oxide, ruthenium oxide, zincoxide, or the like is given. Of the metal oxides described above, anoxide of a transition metal belonging to any of Groups 4 to 8 of theperiodic table of the elements is preferable for its highelectron-accepting property. In particular, vanadium oxide, molybdenumoxide, tungsten oxide, and rhenium oxide are preferable because they canbe evaporated in vacuum and are easily treated.

In the electron-transporting layer 317 formed with an organic compoundand an inorganic compound having an electron-donating property withrespect to the organic compound, the organic compound is formed byappropriately using the above-mentioned organic compound having anelectron-transporting property. As the inorganic compound, any inorganiccompound can be used as long as electrons are easily donated to theorganic compound, and various metal oxides or metal nitrides can beused. In particular, an alkali metal oxide, an alkaline earth metaloxide, a rare earth metal oxide, an alkali metal nitride, an alkalineearth metal nitride, and a rare earth metal nitride are preferablebecause such oxides and nitrides are likely to have an electron-donatingproperty. Specifically, lithium oxide, strontium oxide, barium oxide,erbium oxide, lithium nitride, magnesium nitride, calcium nitride,yttrium nitride, lanthanum nitride, or the like is given. In particular,lithium oxide, barium oxide, lithium nitride, magnesium nitride, andcalcium nitride are preferable because they can be evaporated in vacuumand are easily treated.

Since the electron-transporting layer 317 or the hole-transporting layer316 formed with the organic compound and the inorganic compound issuperior in an electron-injecting/transporting property, variousmaterials can be used to form the first conductive layer 121 and thesecond conductive layer 124 without much restriction by the workfunction, and moreover, the drive voltage can be decreased.

The functional layer 123 has a layer (hereinafter, referred to as alight emitting layer 319) which has a light emitting function and isformed using an inorganic compound; therefore, the element 126 functionsas an inorganic EL element. The inorganic EL element is categorized as adispersed inorganic EL element or a thin film inorganic EL element inaccordance with the element structure. They are different in that theformer dispersed inorganic EL element has an electroluminescent layer inwhich particles of a light emitting material are dispersed in a binder,and the latter thin film inorganic EL element has an electroluminescentlayer formed of a thin film made of a light emitting material; however,a common point is that they both require electrons which are acceleratedby a high electric field. As a mechanism of the obtained emission, thereare two types: donor-acceptor recombination emission in which a donorlevel and an acceptor level are used, and local emission in which innershell electron transition in a metal ion is used. Generally, thedispersed inorganic EL element typically has a donor-acceptorrecombination emission and the thin film inorganic EL element typicallyhas local emission. Hereinafter, a structure of an inorganic EL elementis shown.

The light emitting material which can be used in the present inventionis formed of a host material and an impurity element which becomes aluminescence center. By changing the impurity element to be included,various emission colors can be obtained. As a method for manufacturingthe light emitting material, various methods such as a solid phasemethod, a liquid phase method (a coprecipitation method), or the likecan be used. Alternatively, a spray pyrolysis method, a doubledecomposition method, a method by thermal decomposition reaction of aprecursor, a reversed micelle method, a method in which these methodsand high temperature baking are combined, a liquid phase method such asa freeze-drying method, or the like can be used.

The solid phase method is a method in which a compound including a hostmaterial and an impurity element or a compound including the impurityelement are weighed, mixed in a mortar, heated in an electric furnaceand baked to react so as to include an impurity element in the hostmaterial. The baking temperature is preferably 700° C. to 1500° C. Thisis because solid-phase reaction does not proceed when the temperature istoo low, and the host material is decomposed when the temperature is toohigh. The baking may be performed in a powder state; however, it ispreferably performed in a pellet state. Baking at a relatively hightemperature is required. However, since it is a simple method, highproductivity can be obtained; therefore, it is suitable for massproduction.

The liquid phase method (coprecipitation method) is a method in which ahost material or a compound including the host material, and an impurityelement or a compound including the impurity element are reacted in asolution, dried, and then baked. Since the particles of the lightemitting material are dispersed uniformly, the reaction occurs even ifthe particles are small and baking temperature is low.

As the host material to be used for the light emitting material, asulfide, an oxide, or a nitride can be used. As a sulfide, for example,zinc sulfide (ZnS), cadmium sulfide (CdS), calcium sulfide (CaS),yttrium sulfide (Y₂S₃), gallium sulfide (Ga₂S₃), strontium sulfide(SrS), barium sulfide (BaS), or the like can be used. As an oxide, forexample, zinc oxide (ZnO), yttrium oxide (Y₂O₃), or the like can beused. As a nitride, for example, aluminum nitride (AlN), gallium nitride(GaN), indium nitride (InN), or the like can be used. Alternatively,zinc selenide (ZnSe), zinc telluride (ZnTe), or the like can be alsoused. Furthermore, mixed crystal of a three-dimensional structure suchas calcium sulfide-gallium (CaGa₂S₄), strontium sulfide-gallium(SrGa₂S₄), and barium sulfide-gallium (BaGa₂S₄) may be used.

As a luminescence center of the local emission, manganese (Mn), copper(Cu), samarium (Sm), terbium (Th), erbium (Er), thulium (Tm), europium(Eu), cerium (Ce), praseodymium (Pr), or the like can be used. As chargecompensation, a halogen element such as fluorine (F) or chlorine (Cl)may be added.

On the other hand, as a luminescence center of the donor-acceptorrecombination emission, a light emitting material including a firstimpurity element forming a donor level and a light emitting materialincluding a second impurity element forming an acceptor level can beused. As the first impurity element, for example, fluorine (F), chlorine(Cl), aluminum (Al), or the like can be used. As the second impurityelement, for example, copper (Cu), silver (Ag), or the like can be used.

When a light emitting material of donor-acceptor recombination emissionis synthesized by a solid phase method, a host material, a firstimpurity element or a compound including the first impurity element, anda second impurity element or a compound including the second impurityelement are weighed, mixed in a mortar, heated in an electric furnaceand baked. As the host material, the above-mentioned host materials canbe used. As the first impurity element or the compound including thefirst impurity element, for example, fluorine (F), chlorine (Cl),aluminum sulfide (Al₂S₃), or the like can be used. As the secondimpurity element or the compound including the second impurity element,for example, copper (Cu), silver (Ag), copper sulfide (Cu₂S), silversulfide (Ag₂S), or the like can be used. The baking temperature ispreferably 700° C. to 1500° C. This is because a solid-phase reactiondoes not proceed when the temperature is too low, and the host materialis decomposed when the temperature is too high. The baking may beperformed in a powder state; however it is preferably performed in apellet state.

As an impurity element in the case of using a solid-phase reaction, acombination of compounds formed of the first impurity element and thesecond impurity element may be used. In this case, since the impurityelement is easily dispersed and the solid-phase reaction is easilyadvanced, a uniform light emitting material can be obtained.Furthermore, since no unnecessary impurity element is mixed, the lightemitting material with high purity can be obtained. As the compoundformed of the first impurity element and the second impurity element,for example, copper chloride (CuCl), silver chloride (AgCl), or the likecan be used.

Note that the concentration of these impurity elements is in the rangeof 0.01 to 10 atom % with respect to the host material, preferably, 0.05to 5 atom %.

FIG. 14C shows a cross section of an inorganic EL element in which thefunctional layer 123 includes a first insulating layer 318, the lightemitting layer 319, and a second insulating layer 320.

In the case of a thin film type inorganic EL, the light emitting layer319 is a layer including the light emitting material, and can be formedby a vacuum evaporation method such as a resistance heating vaporevaporation method or an electron beam evaporation (EB evaporation)method, a physical vapor deposition (PVD) method such as a sputteringmethod, a metal organic CVD method, a chemical vapor deposition (CVD)method such as a low-pressure hydride transfer CVD method, an atomiclayer epitaxy (ALE) method, or the like.

The first insulating layer 318 and the second insulating layer 320 arenot particularly limited; however they preferably have a high dielectricstrength voltage, a dense film quality, and a high dielectric constant.For example, silicon oxide (SiO₂), yttrium oxide (Y₂O₃), titanium oxide(TiO₂), aluminum oxide (Al₂O₃), hafnium oxide (HfO₂), tantalum oxide(Ta₂O₅), barium titanate (BaTiO₃), strontium titanate (SrTiO₃), leadtitanate (PbTiO₃), silicon nitride (Si₃N₄), zirconium oxide (ZrO₂), orthe like, a mixed film of these, or a layered film including two or morekinds of these can be used. The first insulating layer 318 and thesecond insulating layer 320 can be formed by sputtering, evaporation,CVD, or the like. The film thickness is not particularly limited;however, it is preferably in the range of 10 nm to 1000 nm. Note thatsince the light emitting element in this embodiment mode is not requiredto have a hot electron, the light emitting element has advantages inthat a thin film can be formed and driving voltage can be reduced. Thelight emitting element preferably has a thickness of 500 nm or less,more preferably a thickness of 100 nm or less.

Note that although not shown, a buffer layer may be provided between thelight emitting layer and the insulating layer or between the lightemitting layer and the electrode. This buffer layer facilitates carrierinjection and functions to suppress mixture of the two layers. Althougha material of the buffer layer is not particularly limited, the hostmaterial of the light emitting layer such as ZnS, ZnSe, ZnTe, CdS, SrS,BaS, CuS, Cu₂S, LiF, CaF₂, BaF₂, or MgF₂ can be used.

In addition, as shown in FIG. 14D, the functional layer 123 may beformed with the light emitting layer 319 and the first insulating layer318. In this case, FIG. 14D shows a state in which the first insulatinglayer 318 is provided between the second conductive layer 124 and thelight emitting layer 319. Note that the first insulating layer 318 maybe provided between the first conductive layer 121 and the lightemitting layer 319.

Furthermore, the functional layer 123 may be formed only with the lightemitting layer 319. That is, the element 126 may be formed with thefirst conductive layer 121, the functional layer 123, and the secondconductive layer 124.

In the case of the dispersed inorganic EL, particulate light emittingmaterials are dispersed in a binder, thereby forming a membranouselectroluminescent layer. When a particle having a desired size cannotbe obtained by a method for manufacturing the light emitting material,the material can be processed by crushing in a mortar or the like toobtain adequate particulate light emitting materials. The binder is asubstance for fixing the particulate light emitting material in adispersed state, and holding it in a form of an electroluminescentlayer. The light emitting material is uniformly dispersed in theelectroluminescent layer by the binder and fixed.

In the case of the dispersed inorganic EL, the electroluminescent layercan be formed by a droplet discharge method in which anelectroluminescent layer can be selectively formed, a printing method(screen printing, offset printing, or the like), a coating method suchas a spin coating method, a dipping method, a dispenser method, or thelike. The film thickness is not particularly limited; however, it ispreferably in the range of 10 nm to 1000 nm. In the electroluminescentlayer including a light emitting material and a binder, the ratio of thelight emitting material is preferably greater than or equal to 50 wt %and less than or equal to 80 wt %.

An element in FIG. 14E includes the first conductive layer 121, thefunctional layer 123, and the second conductive layer 124. Thefunctional layer 123 includes a light emitting layer in which a lightemitting material 326 is dispersed in a binder 325, and the insulatinglayer 318. Note that the insulating layer 318 is in contact with thesecond conductive layer 124 in FIG. 14E; however, the insulating layer318 may be in contact with the first conductive layer 121. In addition,the element may include insulating layers which are in contact with thefirst conductive layer 121 and the second conductive layer 124,respectively. Besides, the element is not required to have insulatinglayers which are in contact with the first conductive layer 121 and thesecond conductive layer 124, respectively.

As the binder which can be used in this embodiment mode, an organicmaterial or an inorganic material can be used. In addition, a mixedmaterial of an organic material and an inorganic material can be used.As the organic material, like a cyanoethyl cellulose resin, a polymerhaving a relatively high dielectric constant; an organic resin such aspolyethylene, polypropylene, a polystyrene resin, a silicone resin, anepoxy resin, vinylidene fluoride; or the like can be used.Alternatively, a thermally stable high molecular material such asaromatic polyamide or polybenzimidazole, or a siloxane resin may beused. Note that the siloxane resin corresponds to a resin containing aSi—O—Si bond. In siloxane, a skeleton structure is constituted by a bondof silicon (Si) and oxygen (O). As a substituent, an organic groupincluding at least hydrogen (for example, alkyl group, or aromatichydrocarbon) is used. As the substituent, a fluoro group may also beused. Alternatively, an organic group including at least hydrogen andfluoro group may be used as a substituent. Alternatively, a resinmaterial such as a vinyl resin like polyvinyl alcohol, polyvinylbutyral, or the like, a phenol resin, a novolac resin, an acrylic resin,a melamine resin, an urethane resin, or an oxazole resin(polybenzoxazole) can be used. Furthermore, a photo-curing resinmaterial or the like can be used. The dielectric constant can beadjusted by adequately mixing fine particles with a high dielectricconstant such as barium titanate (BaTiO₃) or strontium titanate (SrTiO₃)into these resins.

The inorganic material included in the binder can be formed of siliconoxide (SiO_(x)), silicone nitride (SiN_(x)), silicon including oxygenand nitrogen, aluminum nitride (AlN), aluminum including oxygen andnitrogen or aluminum oxide (Al₂O₃), titanium oxide (TiO₂), BaTiO₃,SrTiO₃, lead titanate (PbTiO₃), potassium niobate (KNbO₃), lead niobate(PbNbO₃), tantalum oxide (Ta₂O₅), barium tantalate (BaTa₂O₆), lithiumtantalate (LiTaO₃), yttrium oxide (Y₂O₃), zirconium oxide (ZrO₂), ZnS,or another material selected from a substance including other inorganicmaterials. By adding the inorganic material having a high dielectricconstant to the organic material (using a doping method or the like),the dielectric constant of the electroluminescent layer made from thelight emitting material and the binder can be controlled moreefficiently, and the dielectric constant can be increased further.

In a manufacturing process, a light emitting material is dispersed in asolution including a binder. As a solvent of solution including thebinder which can be used for this embodiment mode, a solvent in which abinder material is dissolved, and a solution having a viscosity suitablefor a method for forming a light emitting layer (various wet processes)and for a desired film thickness can be formed, is selected asappropriate. In the case where the organic solvent or the like can beused, for example, a siloxane resin is used as a binder, propyleneglycol monomethylether, propylene glycol monomethylether acetate (alsoreferred to as PGMEA), 3-methoxy-3-methyl-1-butanol (also referred to asMMB), or the like can be used.

The inorganic EL light emitting element can obtain light emission byapplying voltage between a pair of electrode layers sandwiching theelectroluminescent layer; however, the light emitting element canoperate either in AC drive or DC drive.

In the case where the element 126 is a diode or a photoelectricconversion element, a material whose electric property is changed byirradiation with light is used for the functional layer 123. As amaterial whose electric property is changed by irradiation with light,there are an inorganic semiconductor material, an organic compound, andthe like.

An inorganic semiconductor can be formed using amorphous silicon,amorphous silicon germanium, microcrystal silicon, microcrystal silicongermanium, or the like by a CVD method, a sputtering method, or thelike. As an organic compound, an organic semiconductor material ispreferably used; typically, it is desirable to use a α-electronconjugated high molecular material that has skeleton including aconjugated double bond. Typically, soluble high molecular materials maybe used, such as polythiophene, poly(3-alkylthiophene), a polythiophenederivative, and pentacene. Alternatively, the semiconductor layers canbe formed by forming a soluble precursor and then treating it. Theorganic semiconductor material obtained by using a precursor includespolythienylenevinylene, poly(2,5-thienylenevinylene), polyacetylene, apolyacetylene derivative, polyallylenevinylene, and the like. Theprecursor is converted into the organic semiconductor not only byperforming heat treatment but also by adding a reaction catalyst such asa hydrogen chloride gas. These soluble organic semiconductor materialscan be dissolved in a solvent, typically such as toluene, xylene,chlorobenzene, dichlorobenzene, anisole, chloroform, dichloromethane,γ-butyrlactone, butylcellosolve, cyclohexane, NMP(N-methyl-2-pyrrolidone), cyclohexanone, 2-butanone, dioxane,dimethylformamide (DMF), and tetrahydrofuran (THF). Furthermore, thefunctional layer 123 can be formed as a bonding layer of acharge-generating layer and a charge-accepting layer formed with anorganic compound.

Here, a mode in which the functional layer 123 is formed as a bondinglayer of a charge-generating layer and a charge-accepting layer isdescribed with reference to FIGS. 15A to 15D.

As shown in FIG. 15A, a photoelectric conversion element and a diodeeach have a layered structure in which the first conductive layer 121, acharge-generating layer 321, a charge-accepting layer 322, and thesecond conductive layer 124 are provided sequentially.

The first conductive layer 121 or the second conductive layer 124 isformed with a conductive layer having a light transmitting property. Thecharge-generating layer 321 and the charge-accepting layer 322 may beformed by appropriately selecting the above-mentioned organic compoundhaving the hole-transporting property and organic compound having theelectron-transporting property cited in the description of the layer 300including the organic compound shown in FIG. 13A. Moreover, as theorganic compound having the electron-transporting property, a perylenederivative, a naphthalene derivative, a quinone derivative,methylviologen, fullerene, an organic metal compound containingruthenium, platinum, titanium, or the like may be used. Here, thecharge-generating layer 321 is formed with a compound having ahole-transporting property, and the charge-accepting layer 322 is formedwith a compound having an electron-transporting property.

As shown in FIG. 15B, an electron-transporting layer 323 formed with anorganic compound having an electron-transporting property and aninorganic compound having an electron-donating property with respect tothe organic compound may be provided instead of the charge-acceptinglayer 322. The electron-transporting layer 323 can be formed byappropriately selecting a compound shown as the electron-transportinglayer 317 in FIG. 14B, which is formed with the organic compound havingthe electron-transporting property and the inorganic compound having theelectron-donating property with respect to the organic compound.

As shown in FIG. 15C, an electron-generating layer 324 formed with anorganic compound having a hole-transporting property and an inorganiccompound having an electron-accepting property with respect to theorganic compound may be provided instead of the charge-generating layer321. The electron-generating layer 324 can be formed by appropriatelyselecting a compound shown as the hole-transporting layer 316 in FIG.14B, which is formed with the organic compound having theelectron-transporting property and the inorganic compound having theelectron-accepting property with respect to the organic compound.

As shown in FIG. 15D, the electron-generating layer 324 formed with anorganic compound having a hole-transporting property and an inorganiccompound having an electron-accepting property with respect to theorganic compound, and the electron-transporting layer 323 formed withthe organic compound having the electron-transporting property and theinorganic compound having the electron-donating property with respect tothe organic compound, may be provided.

When the layer including the organic compound is formed with thecharge-generating layer and the charge-accepting layer which are joined,electrons and holes generated in the charge-generating layer can be usedas electron carriers and hole carriers to become photocurrent.Accordingly, a solar cell and a photoelectric conversion device capableof converting light energy into electrical energy can be manufactured.

When the charge-generating layer or the charge-accepting layer is formedwith an organic compound and an inorganic compound, electron and holegenerating efficiency can be improved. Accordingly, a photoelectricconversion element and a solar cell having high energy conversionefficiency can be achieved.

Embodiment Mode 6

This embodiment mode will describe a typical example of the structure ofthe element forming layer 104 in Embodiment Modes 1 to 4, with referenceto FIGS. 7A to 8D. FIGS. 7A to 7D show a process of manufacturing apassive matrix liquid crystal display device, and FIGS. 8A to 8D show aprocess of manufacturing an active matrix liquid crystal display device.Note that Embodiment Mode 1 is used for description in this embodimentmode; however, any of Embodiment Modes 2 to 4 can be applied. Thisembodiment mode describes a mode in which the element forming layer 104includes a liquid crystal element having a first conductive layer, aliquid crystal layer, and a second conductive layer.

Similarly to Embodiment Mode 1, as shown in FIG. 7A, the photocatalyticlayer 102 is formed over the substrate 101 having the light transmittingproperty, and the organic compound layer 103 is formed over thephotocatalytic layer 102. Next, the insulating layer 120 may be formedover the organic compound layer 103. First conductive layers 151 areformed over the insulating layer 120. The first conductive layers 151are preferably formed to be parallel to each other. Next, an insulatinglayer 152 which functions as an alignment film is formed over the firstconductive layers 151.

By a similar step to the above-described one, a substrate 153 havingflexibility is provided with second conductive layers 154, and thesecond conductive layer is provided with an insulating layer 155 whichfunctions as an alignment film. The second conductive layers 154 arepreferably formed to be parallel to each other, similarly to the firstconductive layers 151.

The insulating layers 152 and 155 which function as the alignment filmscan be formed in such a way that a high molecular compound layer such aspolyimide or polyvinyl alcohol is formed by a printing method, a rollcoating method, or the like, and then rubbing treatment is performed. Inaddition, the insulating layers 152 and 155 which function as thealignment films can be formed by obliquely evaporating SiO onto asubstrate. Further, the insulating layers 152 and 155 which function asthe alignment films can be formed by irradiating a photoreactive-typehigh molecular compound with polarized UV light, and polymerizing thephotoreactive-type high molecular compound.

In this embodiment mode, the first conductive layers 151 and the secondconductive layers 154 can be formed using the material and the methodfor manufacturing the first conductive layer 121 and the secondconductive layer 124 shown in Embodiment Mode 5, as appropriate. Notethat in the case where a liquid crystal display device is a transmissiveliquid crystal display device, the first conductive layers 151 and thesecond conductive layers 154 are formed with conductive layers havinglight transmitting properties. Further, in the case where a liquidcrystal display device is a reflective liquid crystal display device,one of the first conductive layer 151 and the second conductive layer154 is formed with a conductive layer having a light transmittingproperty, and the other of the first conductive layer 151 and the secondconductive layer 154 is formed with a conductive layer having areflective property.

In order to keep a space between the substrate 101 having the lighttransmitting property and the substrate 153 having flexibility, a spacermay be provided between the insulating layers 152 and 155. Further,after a spacer is provided over the insulating layer 120 or thesubstrate 153 having flexibility, the insulating layer 152 or theinsulating layer 155 may be formed. As the spacer, an organic resin isapplied, and the organic resin is formed into a desired shape, typicallythe organic resin is etched into a pillar shape or a columnar shape. Inaddition, a bead spacer may be used as a spacer.

Note that a colored layer may be provided between the second conductivelayer 154 and the substrate 153 having flexibility. The colored layer isrequired to perform color display, and in the case of an RGB system,colored layers corresponding to respective colors of red, green, andblue are provided corresponding to each pixel.

Next, the substrate 101 having the light transmitting property and thesubstrate 153 having flexibility are attached to each other using asealing material 157. A liquid crystal layer 156 is formed between thesubstrate 101 having the light transmitting property and the substrate153 having flexibility. The substrate 101 having the light transmittingproperty and the substrate 153 having flexibility are attached to eachother using the sealing material such that the first conductive layers151 and the second conductive layers 154 intersect with each other. Theliquid crystal layer 156 can be formed by a vacuum injection methodusing capillary phenomenon, and injecting a liquid crystal material intoa region surrounded by the substrate 101 having the light transmittingproperty, the substrate 153 having flexibility, and the sealing material157. One of the substrate 101 having the light transmitting property andthe substrate 153 having flexibility is provided with the sealingmaterial 157 and a liquid crystal material is dropped in a regionsurrounded by the sealing material, and then, the substrate having thelight transmitting property and the substrate having flexibility arepressure-bonded to each other using the sealing material in reducedpressure, so that the liquid crystal layer 156 can be formed.

The sealing material 157 can be formed using a heat curing type epoxyresin, a UV curing type acrylic resin, thermoplastic nylon, polyester,or the like by a dispenser method, a printing method, athermo-compression bonding method, or the like. Note that filler isdispersed in the sealing material 157, so that the substrate 101 havingthe light transmitting property and the substrate 153 having flexibilitycan keep a space therebetween.

As the substrate 153 having flexibility, a similar one to the substratehaving flexibility which can be provided over the surface of the elementforming layer 104 shown in Embodiment Mode 1 can be selected asappropriate.

Next, as shown in FIG. 7B, the photocatalytic layer 102 is irradiatedwith the light 105 through the substrate 101 having the lighttransmitting property. As a result of this, the photocatalytic layer 102is activated. Accordingly, the photocatalytic layer 102 and the organiccompound layer 103 are separated from each other as shown in FIG. 7C.

By the above-described steps, as shown in FIG. 7C, a semiconductordevice 158 which includes a liquid crystal element 150 and the organiccompound layer 103 and which functions as a liquid crystal displaydevice can be formed. Note that after a separating step shown in FIG.7C, the surface of the organic compound layer 103 may be provided withthe substrate 130 having flexibility, so that a semiconductor device 159as shown in FIG. 7D may be formed.

In addition, as shown in FIG. 8A, an element forming layer may beprovided with a switching element which is connected to a liquid crystalelement 162. As a switching element, there are a thin film transistor,MIM (Metal-Insulator-Metal), a diode, and the like. A mode in which thethin film transistor 141 is used as a switching element is shown here.

That is, as shown in FIG. 8A, the photocatalytic layer 102 is formedover the substrate 101 having the light transmitting property, and theorganic compound layer 103 is formed over the photocatalytic layer 102.Next, the thin film transistor 141 which functions as a switchingelement is formed over the organic compound layer 103. Next, a firstconductive layer 161 connected to the wirings of the thin filmtransistor 141 is formed over an insulating layer 160. Note that thewirings 1405 of the thin film transistor 141 and the first conductivelayer 161 are connected to each other with the insulating layer 160interposed therebetween; however, the present invention is not limitedto this structure, and the first conductive layer 161 may be formed withthe wiring of the thin film transistor 141. Note that the firstconductive layer 161 is formed in each pixel.

In addition, the substrate 153 having flexibility is provided with thesecond conductive layers 154 and the insulating layer 155 whichfunctions as an alignment film. The second conductive layers 154 may beformed over the entire surface of a pixel portion so that the secondconductive layers 154 can serve as a common electrode of each pixel.

Next, the substrate 101 having the light transmitting property and thesubstrate 153 having flexibility are attached to each other with thesealing material 157. In addition, the liquid crystal layer 156 isformed between the substrate 101 having the light transmitting propertyand the substrate 153 having flexibility.

Next, as shown in FIG. 8B, the photocatalytic layer 102 is irradiatedwith the light 105 through the substrate 101 having the lighttransmitting property. As a result of this, the photocatalytic layer 102is activated. Accordingly, the photocatalytic layer 102 and the organiccompound layer 103 are separated from each other as shown in FIG. 8C.

By the above-described steps, as shown in FIG. 8C, a semiconductordevice 163 which includes the liquid crystal element 162 and the organiccompound layer 103 can be formed. Note that after a separating stepshown in FIG. 8C, the surface of the organic compound layer 103 may beprovided with the substrate 130 having flexibility, so that asemiconductor device 164 as shown in FIG. 8D may be formed.

By the above-described steps, a semiconductor device having flexibilitycan be formed.

Embodiment Mode 7

This embodiment mode will describe a typical example of the structure ofthe element forming layer 104 in Embodiment Modes 1 to 4, with referenceto FIGS. 9A to 10D. FIGS. 9A to 9D show a process of manufacturing apassive matrix electrophoretic display device having an electrophoresiselement, and FIGS. 10A to 10D show a process of manufacturing an activematrix electrophoretic display device having an electrophoresis element.Note that Embodiment Mode 1 is used for description in this embodimentmode; however, any of Embodiment Modes 2 to 4 can be applied. Anelectrophoresis element means an element in which a microcapsulecontaining black and white particles which are charged positively andnegatively is arranged between the first conductive layer and the secondconductive layer, and a potential difference is generated between thefirst conductive layer and the second conductive layer, so that theblack and white particles can move between electrodes to performdisplay.

Similarly to Embodiment Mode 1, as shown in FIG. 9A, the photocatalyticlayer 102 is formed over the substrate 101 having the light transmittingproperty, and the organic compound layer 103 is formed over thephotocatalytic layer 102. Next, the insulating layer 120 may be formedover the organic compound layer 103. Next, first conductive layers 171are formed over the insulating layer 120. The first conductive layers171 are preferably formed to be parallel to each other.

By a similar step to the above-described one, a substrate 172 havingflexibility is provided with second conductive layers 173. The secondconductive layers 173 are preferably formed to be parallel to eachother.

The first conductive layers 171 and the second conductive layers 173 canbe formed using the material and the method for manufacturing the firstconductive layer 121 and the second conductive layer 124 shown inEmbodiment Mode 5, as appropriate.

Next, the substrate 101 having the light transmitting property and thesubstrate 172 having flexibility are attached to each other using asealing material. An electrophoresis element is formed between thesubstrate 101 having the light transmitting property and the substrate172 having flexibility. The substrate 101 having the light transmittingproperty and the substrate 172 having flexibility are attached to eachother using the sealing material such that the first conductive layers171 and the second conductive layers 173 intersect with each other.Further, the electrophoresis element includes the first conductive layer171, a microcapsule 170, and the second conductive layer 173. Inaddition, the microcapsule 170 is fixed between the first conductivelayer 171 and the second conductive layer 173 with a binder.

Next, a structure of the microcapsule is shown with reference to FIGS.17A to 17D. As shown in FIGS. 17A and 17B, in the microcapsule 170, atransparent dispersion medium 176, a charged black particle 175 a, and acharged white particle 175 b are dispersed in a fine transparentcontainer 174. Note that a blue particle, a red particle, a greenparticle, a yellow particle, a blue-green particle, or a purplish redparticle may be used instead of the black particle 175 a. Further, asshown in FIGS. 17C and 17D, a microcapsule 330 in which a coloreddisperse medium 333 and a white particle 332 are dispersed in a finetransparent container 331 may be used. Note that the colored dispersemedium 333 may be colored in any of black, blue, red, green, yellow,blue green, and reddish violet. In addition, when each of a microcapsulein which blue particles are dispersed, a microcapsule in which redparticles are dispersed, and a microcapsule in which green particles aredispersed are provided in one pixel, color display can be performed. Inaddition, when each of a microcapsule in which yellow particles aredispersed, a microcapsule in which blue green particles are dispersed,and a microcapsule in which reddish violet particles are dispersed areprovided in one pixel, color display can be performed. Further, wheneach of a microcapsule having a blue dispersion medium, a microcapsulehaving a red dispersion medium, and a microcapsule having a greendispersion medium are arranged in one pixel, and each of themicrocapsules includes either white particles or black particles, colordisplay can be performed. In addition, when each of a microcapsulehaving a yellow dispersion medium, a microcapsule having a blue greendispersion medium, and a microcapsule having a reddish violet dispersionmedium are arranged in one pixel, color display can be performed.

Next, a display method using an electrophoresis element is shown.Specifically, FIGS. 17A and 17B are used to show a display method of themicrocapsule 170 having two color particles. Here, a white particle anda black particle are used as two color particles, and a microcapsulehaving a transparent dispersion medium is shown. Note that a particlehaving another color particle may be used instead of the black particleof the two color particles.

In the microcapsule 170, when the black particulate 175 a is chargedpositively and the white particle 175 b is charged negatively, voltageis applied to the first conductive layers 171 and the second conductivelayers 173. As shown in FIG. 17A, when an electric field is generated ina direction from the second conductive layer to the first conductivelayer here, the black particle 175 a migrates to the second conductivelayer 173 side, and the white particle 175 b migrates to the firstconductive layer 171 side. Accordingly, when the microcapsule is seenfrom the first conductive layer 171 side, white is observed, and whenthe microcapsule is seen from the second conductive layer 173 side,black is observed.

On the other hand, when voltage is applied in a direction from the firstconductive layers 171 to the second conductive layers 173 as shown inFIG. 17B, the black particle 175 a migrates to the first conductivelayer 171 side and the white particle 175 b migrates to the secondconductive layer 173 side. Accordingly, when the microcapsule is seenfrom the first conductive layer 171 side, white is observed, and whenthe microcapsule is seen from the second conductive layer 173 side,black is observed.

Next, a display method of the microcapsule 330 having the white particleand the colored dispersion medium is shown. Although an example in whicha dispersion medium is colored in black is shown here, a dispersionmedium colored in another color can be similarly used.

In the microcapsule 330, when the white particle 332 is chargednegatively, voltage is applied to the first conductive layer 171 and thesecond conductive layer 173. As shown in FIG. 17C, when an electricfield is generated in a direction from the second conductive layer tothe first conductive layer here, the white particle 175 b migrates tothe first conductive layer 171 side. Accordingly, when the microcapsuleis seen from the first conductive layer 171 side, white is observed, andwhen the microcapsule is seen from the second conductive layer 173 side,black is observed.

On the other hand, as shown in FIG. 17D, when an electric field isgenerated in a direction from the first conductive layer to the secondconductive layer, the white particle 175 b migrates to the secondconductive layer 173 side. Accordingly, when the microcapsule is seenfrom the first conductive layer 171 side, white is observed, and whenthe microcapsule is seen from the second conductive layer 173 side,black is observed.

Although an electrophoresis element is used for description here, adisplay device using a twist ball display method may be used instead ofthe electrophoresis element. A twist ball display method means a methodin which a spherical particle which is white on one hemisphericalsurface and black on the other hemispherical surface is arranged betweenthe first conductive layer and the second conductive layer, and apotential difference is generated between the first conductive layer andthe second conductive layer to control a direction of the sphericalparticle, so that display is performed.

As the substrate 172 having flexibility, a similar one to the substratehaving flexibility which can be provided over the surface of the elementforming layer 104 shown in Embodiment Mode 1 can be selected asappropriate.

Next, as shown in FIG. 9B, the photocatalytic layer 102 is irradiatedwith the light 105 through the substrate 101 having the lighttransmitting property. As a result of this, the photocatalytic layer 102is activated. Accordingly, the photocatalytic layer 102 and the organiccompound layer 103 are separated from each other as shown in FIG. 9C.

By the above-described steps, as shown in FIG. 9C, a semiconductordevice 177 which includes the electrophoresis element and the organiccompound layer 103 can be formed. Note that after a separating stepshown in FIG. 9C, the surface of the organic compound layer 103 may beprovided with the substrate 130 having flexibility, so that asemiconductor device 178 as shown in FIG. 9D may be formed.

In addition, as shown in FIG. 10A, a switching element may be connectedto the electrophoresis element. As a switching element, there are a thinfilm transistor, MIM (Metal-Insulator-Metal), a diode, and the like. Amode in which the thin film transistor 141 is used as a switchingelement is shown here.

That is, as shown in FIG. 8A, the photocatalytic layer 102 is formedover the substrate 101 having the light transmitting property, and theorganic compound layer 103 is formed over the photocatalytic layer 102.Next, the insulating layer 120 is formed over the organic compound layer103, and the thin film transistor 141 which functions as a switchingelement is formed over the organic compound layer 103. Next, a firstconductive layer 181 connected to the wiring of the thin film transistor141 is formed over an insulating layer 180. Note that the wiring of thethin film transistor 141 and the first conductive layer 181 areconnected to each other with the insulating layer 180 interposedtherebetween; however, the present invention is not limited to thisstructure, and the first conductive layer 181 may be formed with thewiring of the thin film transistor 141. Note that the first conductivelayer 181 is formed in each pixel.

In addition, the substrate 172 having flexibility is provided with thesecond conductive layers 173. The second conductive layers 173 may beformed over the entire surface of a pixel portion so that the secondconductive layers 173 can serve as a common electrode of each pixel.

Next, the substrate 101 having the light transmitting property and thesubstrate 172 having flexibility are attached to each other with asealing material. In addition, an electrophoresis element is formedbetween the substrate 101 having the light transmitting property and thesubstrate 172 having flexibility.

Next, as shown in FIG. 10B, the photocatalytic layer 102 is irradiatedwith the light 105 through the substrate 101 having the lighttransmitting property. As a result of this, the photocatalytic layer 102is activated. Accordingly, the photocatalytic layer 102 and the organiccompound layer 103 are separated from each other as shown in FIG. 10C.

A display device having an electrophoresis element and a display deviceusing a twist ball display method keep a state similar to when anelectric field is applied, for a long term after a field effecttransistor is removed. Therefore, a display state can be held even afterthe power is turned off. Accordingly, low power consumption is possible.

By the above-described steps, a semiconductor device 182 which includesthe electrophoresis element and the organic compound layer 103 can beformed. Note that after a separating step shown in FIG. 10C, the surfaceof the organic compound layer 103 may be provided with the substrate 130having flexibility, so that a semiconductor device 183 as shown in FIG.10D may be formed.

Embodiment Mode 8

This embodiment mode will describe a typical example of the structure ofthe element forming layer 104 in Embodiment Modes 1 to 4, with referenceto FIGS. 11A to 11D. FIGS. 11A to 11D show a process of manufacturing asemiconductor device having a thin film transistor. Note that EmbodimentMode 1 is used for description in this embodiment mode; however, any ofEmbodiment Modes 2 to 4 can be applied.

Similarly to Embodiment Mode 1, as shown in FIG. 11A, the photocatalyticlayer 102 is formed over the substrate 101 having the light transmittingproperty, and the organic compound layer 103 is formed over thephotocatalytic layer 102. Next, the insulating layer 120 may be formedover the organic compound layer 103. Next, the thin film transistor 141is formed over the organic compound layer 103. Here, reference numerals191, 192, and 193 show an interlayer insulating layer, a substratehaving flexibility, and an adhesive agent, respectively.

Next, as shown in FIG. 11B, the photocatalytic layer 102 is irradiatedwith the light 105 through the substrate 101 having the lighttransmitting property. As a result of this, the photocatalytic layer 102is activated. Accordingly, the photocatalytic layer 102 and the organiccompound layer 103 are separated from each other as shown in FIG. 11C.

By the above-described steps, a semiconductor device 194 which includesthe thin film transistor 141 and the organic compound layer 103 can beformed. Note that after a separating step shown in FIG. 11C, the surfaceof the organic compound layer 103 may be provided with the substrate 130having flexibility, so that a semiconductor device 195 as shown in FIG.11D may be formed.

Embodiment Mode 9

This embodiment mode will describe a typical example of the structure ofthe element forming layer 104 in Embodiment Modes 1 to 4, with referenceto FIGS. 12A to 12D. FIGS. 12A to 12D show a process of manufacturing asemiconductor device which functions as a solar cell. Note thatEmbodiment Mode 1 is used for description in this embodiment mode;however, any of Embodiment Modes 2 to 4 can be applied.

Similarly to Embodiment Mode 1, as shown in FIG. 12A, the photocatalyticlayer 102 is formed over the substrate 101 having the light transmittingproperty, and the organic compound layer 103 is formed over thephotocatalytic layer 102. Next, the insulating layer 120 may be formedover the organic compound layer 103.

Next, first conductive layers 202 a to 202 c are formed over theinsulating layer 120. Then, photoelectric conversion layers 203 a to 203c are formed so as to expose a part of the first conductive layers 202 ato 202 c. Next, second conductive layers 204 a to 204 c are formed overthe photoelectric conversion layers 203 a to 203 c and a part of anexposed portion of each of the first conductive layers 202 a to 202 c.Here, a photoelectric conversion element 201 a is formed with the firstconductive layer 202 a, the photoelectric conversion layer 203 a, andthe second conductive layer 204 a. In addition, a photoelectricconversion element 201 b is formed with the first conductive layer 202b, the photoelectric conversion layer 203 b, and the second conductivelayer 204 b. Further, a photoelectric conversion element 201 c is formedwith the first conductive layer 202 c, the photoelectric conversionlayer 203 c, and the second conductive layer 204 c. Note that in orderto connect the photoelectric conversion elements 201 a to 201 c inseries, the second conductive layer 204 a of the photoelectricconversion element 201 a is formed so as to be in contact with the firstconductive layer 202 b of the second photoelectric conversion element201 b. In addition, the second conductive layer 204 b of thephotoelectric conversion element 201 b is formed so as to be in contactwith the first conductive layer 202 c of the third photoelectricconversion element 201 c. The second conductive layer 204 c of thephotoelectric conversion element 201 c is formed so as to be in contactwith the first conductive layer of a fourth photoelectric conversionelement.

The first conductive layer, the functional layer, and the secondconductive layer of the photoelectric conversion element or the diodeshown in Embodiment Mode 5 can be used as appropriate for the firstconductive layers 202 a to 202 c, the photoelectric conversion layers203 a to 203 c, and the second conductive layers 204 a to 204 c,respectively.

An adhesive agent 206 may be used to attach the second conductive layers204 a to 204 c and a substrate 205 having flexibility. The adhesiveagent 127 shown in Embodiment Mode 5 can be used as the adhesive agent206, as appropriate. In addition, as the substrate 205 havingflexibility, a similar one to the substrate having flexibility which canbe provided over the surface of the element forming layer 104 shown inEmbodiment Mode 1 can be selected as appropriate.

Next, as shown in FIG. 12B, the photocatalytic layer 102 is irradiatedwith the light 105 through the substrate 101 having the lighttransmitting property. As a result of this, the photocatalytic layer 102is activated. Accordingly, the photocatalytic layer 102 and the organiccompound layer 103 are separated from each other as shown in FIG. 12C.

By the above-described steps, a semiconductor device 207 which functionsas a solar cell can be formed. Note that after a separating step shownin FIG. 12C, the surface of the organic compound layer 103 may beprovided with the substrate 130 having flexibility, so that asemiconductor device 208 as shown in FIG. 12D may be formed.

Embodiment 1

This embodiment will describe a liquid crystal display panel formedusing the present invention, with reference to FIGS. 18A and 18B. In aliquid crystal display panel, a first substrate 600 having flexibility,a second substrate 664 having flexibility, and a liquid crystal layer674 are sealed with a sealing material 650. The sealing material 650preferably includes a holding material which holds a space betweensubstrates, typified by filler. In addition, the first substrate 600having flexibility is bonded to the organic compound layer 103 using anadhesive agent (not shown).

A driver circuit portion 662 and a pixel portion 663 are formed in sucha way that they are surrounded by the sealing material 650, the firstsubstrate 600 having flexibility, and the second substrate 664 havingflexibility. Moreover, a terminal portion 661 is provided outside thesealing material 650.

The second substrate 664 having flexibility is provided with a coloredlayer 665 which functions as a color filter or a black matrix, a secondpixel electrode 666, and an insulating layer 667 which functions as analignment film. In addition, one or both of the first substrate 600having flexibility and the second substrate 664 having flexibility isprovided with a polarizing plate.

At the terminal portion 661, a connecting terminal connected to a sourceor gate wiring of each TFT (a connecting terminal 654 connected to thegate wiring shown in FIG. 18A) is formed. The connecting terminal isconnected to an FPC (Flexible Printed Circuit) 655 which serves as aninput terminal through an anisotropic conductive film 656 and theconnecting terminal receives a video signal or a clock signal throughthe anisotropic conductive film 656.

In the driver circuit portion 662, a circuit for driving a pixel, suchas a source driver and a gate driver is formed. Here, an N-channel TFT651 and a P-channel TFT 652 are arranged. Note that the N-channel TFT651 and the P-channel TFT 652 form a CMOS circuit.

In the pixel portion 663, a plurality of pixels is formed, and a liquidcrystal element 668 is formed in each pixel. The liquid crystal element668 is a portion in which a first pixel electrode 672, the second pixelelectrode 666, and the liquid crystal layer 674 which fills the gapbetween the first pixel electrode 672 and the second pixel electrode 666overlap with each other. The first pixel electrode 672 included in theliquid crystal element 668 is electrically connected to a TFT 602. Thesecond pixel electrode 666 of the liquid crystal element 668 is formedon the second substrate 664 side. An insulating layer 673 whichfunctions as an alignment film is formed between the first pixelelectrode 672 and the liquid crystal layer 674, and the insulating layer667 which functions as an alignment film is formed between the secondpixel electrode 666 and the liquid crystal layer 674.

It is preferable that the first substrate 600 and the second substrate664 be kept apart with a fixed distance therebetween in order todecrease display unevenness. Therefore, spacers 675, which aregap-holding materials, are distributed between the first substrate 600and the second substrate 664. Note that here the spacers 675 are formedover an insulating layer which covers the TFTs 651 and 652, and analignment film is formed over the spacers 675 and the first pixelelectrode. In addition, the shape of the spacer 675 is columnar, and thespacer 675 has a curvature at an edge portion. That is, a radius R ofcurvature of an upper end portion of a columnar spacer is 2 μm or less,preferably 1 μm or less. Equal pressure is applied due to such a shape,and excess pressure can be prevented from being applied to one point.Note that a lower end of the spacer indicates a lower end of thecolumnar spacer on the side of the first substrate having flexibility.In addition, an upper end indicates the top portion of the columnarspacer. Further, when the width of a central portion of the columnarspacer in a height direction is L1 and the width of an end portion ofthe columnar spacer on the side of the second substrate havingflexibility is L2, 0.8≦L2/L1≦3 is satisfied. In addition, an anglebetween a tangent plane at the center of the side surface of thecolumnar spacer and a surface of the first substrate having flexibilityor an angle between a tangent plane at the center of the side surface ofthe columnar spacer and a surface of the second substrate havingflexibility is preferably in the range of 65° to 115°. Further, theheight of the spacer is preferably in the range of 0.5 μm to 10 μm or inthe range of 1.2 μm to 5 μm.

The first substrate 600 having flexibility and the second substrate 664having flexibility are provided with polarizing plates 676 and 677respectively. In addition, the polarizing plates 676 and 677 may beprovided with a retardation plate.

The liquid crystal display panel has a backlight 678. The backlight canbe formed with a light emitting member, and a cold-cathode tube, an LED,an EL light emitting device, or the like can be used typically. Thebacklight of this embodiment preferably has flexibility. Furthermore,the backlight may be provided with a reflecting plate and an opticalfilm.

Embodiment 2

This embodiment will show a backlight which can be used in the aboveembodiment below.

As the backlight 678 shown in FIG. 18B, the EL light emitting devicehaving one or both of the organic EL element and the inorganic ELelement in the above-described embodiment mode can be used. In addition,without using the present invention, an EL light emitting device, inwhich a third substrate 681 having flexibility is provided with a layer682 having a light emitting element which includes a first conductivelayer, a light emitting layer, and a second conductive layer, and thethird substrate 681 having flexibility and the layer 682 having thelight emitting element are sealed with a fourth substrate 683 havingflexibility, can be used. Note that the light emitting element can beformed in such a way that the first conductive layer, the light emittinglayer, and the second conductive layer are formed using an ink jetmethod, an evaporation method, a sputtering method, a printing method,or the like, as appropriate.

Note that as the fourth substrate 683 having flexibility of the EL lightemitting device which can be used for the backlight 678, the polarizingplate 676 shown in FIG. 18A may be used. In this case, a layer having alight emitting element is formed over the third substrate 681 havingflexibility, and the third substrate 681 having flexibility and thelayer 682 having the light emitting element are sealed with thepolarizing plate 676. Then, the polarizing plate 676 and the firstsubstrate 600 having flexibility can be attached to each other with anadhesive agent having a light transmitting property. Accordingly, thenumber of substrates having flexibility for forming the backlight can bereduced.

After the layer 682 having the light emitting element is formed over thethird substrate 681 having flexibility, the layer 682 having the lightemitting element and the third substrate 681 having flexibility can beattached to the polarizing plate 676 provided on the first substrate 600having flexibility with an adhesive agent. Accordingly, the number ofsubstrates having flexibility for forming the backlight can be reduced.

After the layer 682 having the light emitting element is formed on onesurface of the polarizing plate 676, the third substrate 681 havingflexibility may be attached to one surface of the layer 682 having thelight emitting element and the polarizing plate 676 using an adhesiveagent, and then the other surface of the polarizing plate 676 and thefirst substrate 600 having flexibility may be attached to each otherusing an adhesive agent. Further, after the layer 682 having the lightemitting element is formed on one surface of the polarizing plate 676,the other surface of the polarizing plate 676 and the first substrate600 having flexibility may be attached to each other using an adhesiveagent, and then the third substrate 681 having flexibility may beattached to one surface of the polarizing plate 676 using an adhesiveagent. Accordingly, the number of substrates having flexibility forforming the backlight can be reduced.

Furthermore, the polarizing plate 676 may be used instead of the firstsubstrate 600 having flexibility. That is, the polarizing plate 676which seals the third substrate 681 having flexibility and the layer 682having the light emitting element may be attached to the organiccompound layer 103 shown in FIG. 18A, using an adhesive agent.Accordingly, the number of substrates having flexibility for forming theliquid crystal display panel can be reduced.

Light emitting elements with a large area which cover a pixel portioncan be formed as light emitting elements formed in the layer 682 havingthe light emitting element of this embodiment. Elements which emit whitelight are preferably used as such light emitting elements.

In addition, light emitting elements with a line shape may be formed aslight emitting elements formed in the layer 682 having the lightemitting element. Elements which emit white light can be used as thelight emitting elements. Further, light emitting elements are preferablyarranged such that a blue light emitting element, a red light emittingelement, and a green light emitting element are provided in each pixel.In this case, the colored layer 665 shown in FIG. 18A is not necessarilyrequired to be provided. Note that when the colored layer 665 shown inFIG. 18A is provided, color purity is increased and a liquid crystaldisplay panel capable of performing bright display is provided.

In addition, as a light emitting element formed in the layer 682 havingthe light emitting element, an element which emits white light can beused in each pixel. Further, a sub-pixel including a blue light emittingelement, a sub-pixel including a red light emitting element, and asub-pixel including a green light emitting element may be provided ineach pixel. Accordingly, a liquid crystal display panel capable ofhigh-definition display is provided.

Note that the structure of the backlight can also be used for otherliquid crystal display panels than one in the present invention.

Embodiment 3

In this embodiment, as a backlight which can be used in the aboveexamples, a backlight in which a substrate having flexibility isprovided with an LED is described below.

FIG. 19A is a top view of a backlight, and FIG. 19B is a cross sectionalview along a line H-G of FIG. 19A. In FIGS. 19A and 19B, a commonelectrode layer 6001 having a reflective property is provided over asubstrate 6000 having flexibility, and a wiring layer 6002 a and awiring layer 6002 b which function as anodes are formed over aninsulating layer 6006. A light emitting diode 6003 a and a lightemitting diode 6003 b are provided over the wiring layer 6002 a and thewiring layer 6002 b respectively. A connecting terminal 6012 a of thelight emitting diode 6003 a is electrically connected to the wiringlayer 6002 a with conductive particles 6008 in an anisotropic conductivefilm. In addition, a connecting terminal 6013 a of the light emittingdiode 6003 a is electrically connected to the common electrode layer6001 with the conductive particles 6008 in the anisotropic conductivefilm at an opening (a contact hole) 6004 b which is formed in theinsulating layer 6006. Similarly, a connecting terminal 6012 b of thelight emitting diode 6003 b is electrically connected to the wiringlayer 6002 a with the conductive particles 6008 in the anisotropicconductive film, and a connecting terminal 6013 b of the light emittingdiode 6003 b is electrically connected to the common electrode layer6001 at an opening (a contact hole) 6004 a which is formed in theinsulating layer 6006.

Note that as the anisotropic conductive film, the conductive particles6008 are dispersed in an organic resin 6012, and the conductiveparticles 6008 in the organic resin are connected to each other bypressure bonding from one direction. Further, the anisotropic conductivefilm is provided over the entire surface of the substrate havingflexibility here; however, only connecting portions of the lightemitting diode and the wiring layer may be selectively provided with theanisotropic conductive film. Furthermore, an anisotropic conductiveresin may be used instead of the anisotropic conductive film.

The common electrode layer 6001 serves as a reflecting electrode whichreflects incident light. Therefore, light emitted from the lightemitting diodes 6003 a and 6003 b can be efficiently delivered to aliquid crystal display device.

FIG. 20A is a top view of a backlight, and FIG. 20B is a cross sectionalview along a line I-J of FIG. 20A. The backlight of FIGS. 20A and 20B isan example in which a light emitting diode and a common electrode layeror a wiring layer are connected with a bump or a conductive metal paste(e.g., a silver (Ag) paste). In FIG. 20A, the wiring layer 6002 a, thewiring layer 6002 b, and a wiring layer 6002 c are formed linearly. Avoltage to be applied to the wiring layer is easily controlled whenlight emitting diodes of the same color are arranged with respect toeach wiring layer, such that a light emitting diode (the light emittingdiode 6003 a or the like) which is connected to the wiring layer 6002 ais a red light emitting diode (R), a light emitting diode (the lightemitting diode 6003 b or the like) which is connected to the wiringlayer 6002 b is a green light emitting diode (G), and a light emittingdiode (a light emitting diode 6003 c or the like) which is connected tothe wiring layer 6002 c is a blue light emitting diode (B). The lightemitting diode 6003 a is electrically connected to the common electrodelayer 6001 and the wiring layer 6002 a with a conductive paste 6008, andthe light emitting diode 6003 b is electrically connected to the commonelectrode layer 6001 and the wiring layer 6002 a with the conductivepaste 6008.

FIG. 21A is a top view of a backlight, and FIGS. 21B and 21C are crosssectional views along a line K-L of FIG. 21A. The backlight of FIGS. 21Ato 21C has a structure in which a reflective electrode layer and acommon electrode layer are separately provided.

In FIG. 21B, a reflective electrode layer 6021 is formed over thesubstrate 6000 having flexibility, and the insulating layer 6006 isformed over the reflective electrode layer 6021. Wiring layers 6022 aand 6022 b and common electrode layers 6023 a and 6023 b are formed overthe insulating layer 6006. In addition, the light emitting diode 6003 ais provided over the wiring layer 6022 a and the common electrode layer6023 a. Further, the light emitting diode 6003 b is provided over thewiring layer 6022 b and the common electrode layer 6023 b. A connectingterminal 6014 a of the light emitting diode 6003 a is electricallyconnected to the wiring layer 6022 a through a conductive paste 6008 a,and a connecting terminal 6015 a of the light emitting diode 6003 a iselectrically connected to the common electrode layer 6023 a through aconductive paste 6008 b. A connecting terminal 6014 b of the lightemitting diode 6003 b is electrically connected to the wiring layer 6022b through a conductive paste 6008 c, and a connecting terminal 6015 b ofthe light emitting diode 6003 b is electrically connected to the commonelectrode layer 6023 b through a conductive paste 6008 d.

A reflective electrode layer 6021 which reflects incident light isformed over the substrate having flexibility. Therefore, light emittedfrom the light emitting diodes 6003 a and 6003 b can be efficientlydelivered to a liquid crystal display device.

FIG. 21C shows a structure in which an insulating layer 6010 including alight scattering particle 6011 is provided over the reflective electrodelayer 6021. The light scattering particle 6011 includes an effect ofscattering incident light and light reflected by the reflectiveelectrode layer 6021. In this embodiment, the reflective electrode layermay perform specular reflection with its mirror surface. Further, areflective electrode layer which has unevenness on its surface and iswhitened may be used to perform diffuse reflection.

An example in which a plurality of light emitting diodes is providedover a substrate having flexibility is described with reference to FIGS.22A and 22B. A product which includes the backlight having flexibilityis often bent in a particular direction. When seen from the top surface,the backlight in FIG. 22A is a rectangle which is long sideways, and thebacklight is often bent in the directions shown by an arrow 6105 a andan arrow 6105 b. When a top surface shape of the plurality of lightemitting diodes provided over a substrate 6100 having flexibility isrectangular, light emitting diodes 6101 a and 6101 b are arranged suchthat short sides of the light emitting diodes 6101 a and 6101 b areparallel to the long side of the substrate 6100 having flexibility whichis bent with frequency.

The backlight shown in FIG. 22B uses a substrate 6200 having flexibilitywhich is vertically long, and the substrate 6200 having flexibility isoften bent in the directions of an arrow 6205 a and an arrow 6205 b. Inthis case, when seen from a top surface, a plurality of light emittingdiodes provided over the substrate 6200 having flexibility isrectangular. Light emitting diodes 6201 a and 6201 b are arranged suchthat short sides of the light emitting diodes 6201 a and 6201 b areparallel to the side of the substrate 6200 having flexibility which isbent with frequency. In this manner, in the case where there are adirection in which a substrate having flexibility is often bent and adirection in which the substrate having flexibility is not often bentdepending on an intended purpose and the shape of a display device, whena side to be bent and a short side of the light emitting diode arearranged to be parallel in advance so as to be easily bent, the displaydevice becomes hard to be damaged. Therefore, reliability can beincreased.

FIGS. 23A and 23B show a light emitting diode 6401 a and a lightemitting diode 6401 b adjacently provided with a space b therebetween,over a substrate 6400 having flexibility. The light emitting diode 6401a and the light emitting diode 6401 b each have a thickness a. FIG. 23Bis a diagram in which the substrate 6400 having flexibility which isprovided with the light emitting diode 6401 a and the light emittingdiode 6401 b is bent in directions of an arrow 6405 a and an arrow 6405b. As in FIGS. 23A and 23B, when the space b between the adjacent lightemitting diodes is more than twice as large as the thickness a, that is,when b>2a is satisfied, the substrate 6400 having flexibility can bebent easily without the light emitting diode 6401 a and the lightemitting diode 6401 b coming into contact with each other.

FIGS. 24A and 24B show an example of a structure in which a lightemitting diode is covered with a resin layer. As shown in FIG. 24A, alight emitting diode 6151 a covered with a resin layer 6152 a and alight emitting diode 6151 b covered with a resin layer 6152 b are formedover a substrate 6150 having flexibility. In addition, distance betweenthe resin layer 6152 a and the resin layer 6152 b is set to be the spaceb. Each of maximum thicknesses of the resin layer 6152 a and the resinlayer 6152 b is the thickness a. FIG. 24B shows a diagram in which thesubstrate 6150 having flexibility which is provided with the lightemitting diode 6151 a, the resin layer 6152 a, the light emitting diode6151 b, and the resin layer 6152 b is bent in directions of the arrow6154 a and the arrow 6154 b. As in FIGS. 24A and 24B, when the space bbetween the adjacent resin layers and light emitting diodes covered withthe resin layers is more than twice as large as the maximum thickness aof the resin layers covering the light emitting diodes, that is, whenb>2a is satisfied, the substrate 6150 having flexibility can be benteasily without the light emitting diode 6151 a covered with the resinlayer 6152 a and the light emitting diode 6151 b covered with the resinlayer 6152 b coming into contact with each other.

A sidelight type backlight having flexibility shown in FIG. 25 includesa light guide plate 6300 having flexibility, a light emitting diode 6302provided over a substrate 6301 having flexibility, and reflective sheets6303 a and 6303 b which reflect light emitted from the light emittingdiode 6302. The reflective sheets 6303 a and 6303 b are provided so thatlight is efficiently led to the light guide plate. A reflective plate,which is bent in a cylinder shape typified by a conventional reflectorplate, is not easily bent. However, the reflective sheets 6303 a and6303 b having a shape which is not fixed in a cylinder shape in FIG. 25as shown in this embodiment mode can be easily bent.

When a backlight having flexibility with the above structure is used fora display device having flexibility which is formed using atransposition process of the present invention, an electronic apparatushaving flexibility can be formed.

Note that the structure of the backlight can also be used for otherliquid crystal display panels than one in the present invention.

Embodiment 4

Next, an EL display panel is described with reference to FIG. 26.

FIG. 26 shows a cross sectional view of an EL display panel. In the ELdisplay panel, an insulating layer 608 which is provided over the firstsubstrate 600 having flexibility and a second substrate 640 havingflexibility are sealed with the sealing material 650. As the sealingmaterial 650, an epoxy based resin having high viscosity includingfiller is preferably used. A sealing material is desirably a materialwhich transmits as little moisture and oxygen as possible. In addition,the first substrate 600 having flexibility is provided with the organiccompound layer 103.

A driver circuit portion 644 and a pixel portion 645 are included on aninner side of the sealing material 650, the first substrate 600 havingflexibility, and the second substrate 640 having flexibility. Theterminal portion 643 is included on an outer side of the sealingmaterial 650.

At the terminal portion 643, a connecting terminal connected to a sourceor gate wiring of each TFT (the connecting terminal 654 connected to thesource wiring shown in FIG. 26) is formed. The connecting terminal isconnected to the FPC (Flexible Printed Circuit) 655 which serves as aninput terminal through the anisotropic conductive film 656, and theconnecting terminal receives a video signal or a clock signal throughthe anisotropic conductive film 656.

In the driver circuit portion 644, a circuit for driving a pixel, suchas a source driver and a gate driver is formed. Here, the N-channel TFT651 which is formed similarly to the switching TFT 602 in the pixelportion and the P-channel TFT 652 which is formed similarly to thedriving TFT 603 in a pixel portion are arranged. Note that the N-channelTFT 651 and the P-channel TFT 652 form a CMOS circuit.

In the pixel portion 645, pixels each including the switching TFT 602,the driving TFT 603, and a light emitting element 624 are arranged inmatrix. The organic EL element or the inorganic EL element shown in theabove-described embodiment mode can be used as appropriate for the lightemitting element 624. Here, reference numerals 607, 615, 622, and 623show an interlayer insulating layer, a first electrode, a light emittinglayer, and a second electrode, respectively.

Here in this embodiment, FIG. 31 shows an equivalent circuit diagram ofa pixel when a light emitting display device having an organic ELelement performs full-color display. In FIG. 31, a TFT 638 surrounded bydashed lines corresponds to the switching TFT 602 in FIG. 26, and a TFT639 surrounded by dashed lines corresponds to the driving TFT 603.

In the pixel expressing a red color, a drain region of the driving TFT639 is connected to an OLED 703R for emitting red light, while a sourceregion thereof is provided with an anode side power source line (R)706R. The OLED 703R is provided with a cathode side power source line700. The switching TFT 638 is connected to a gate wiring 705 and a gateelectrode of the driving TFT 639 is connected to a drain region of theswitching TFT 638. The drain region of the switching TFT 638 isconnected to a capacitor element 707 connected to the anode side powersource line (R) 706R.

In the pixel expressing a green color, a drain region of the driving TFTis connected to an OLED 703G for emitting green light, while a sourceregion thereof is provided with an anode side power source line (G)706G. The switching TFT 638 is connected to the gate wiring 705 and thegate electrode of the driving TFT 639 is connected to the drain regionof the switching TFT 638. The drain region of the switching TFT 638 isconnected to the capacitor element 707 connected to the anode side powersource line (G) 706G.

In the pixel expressing a blue color, a drain region of the driving TFTis connected to an OLED 703B for emitting blue light, while a sourceregion thereof is provided with an anode side power source line (B)706B. The switching TFT 638 is connected to the gate wiring 705 and thegate electrode of the driving TFT 639 is connected to the drain regionof the switching TFT 638. The drain region of the switching TFT 638 isconnected to the capacitor element 707 connected to the anode side powersource line (B) 706B.

Different voltages in accordance with EL materials are appliedrespectively to the pixels with different colors.

Here, a source wiring 704 is formed in parallel to the anode side powersource lines 706R, 706G, and 706B; however, the present invention is notlimited to this. The gate wiring 705 may be formed in parallel to theanode side power source lines 706R, 706G, and 706B. Moreover, thedriving TFT 639 may have a multi-gate electrode structure.

In the light emitting device, the driving method of screen display isnot particularly limited. For example, a dot-sequential driving method,a line-sequential driving method, a plane-sequential driving method, orthe like may be used. Typically, the line sequential driving method isused, and may be combined with a time-division grayscale driving methodor an area grayscale driving method, as appropriate. In addition, avideo signal to be inputted into a source line of the light emittingdevice may be an analog signal or a digital signal. A driving circuit orthe like may be designed as appropriate in accordance with the videosignal.

Further, in a light emitting device using a digital video signal, thereare two kinds of driving methods in which video signals inputted into apixel are constant voltage (CV) and in which video signals inputted intoa pixel are constant current (CC). Further, as for the driving methodusing video signals with constant voltage (CV), there are two kinds ofmethods in which voltage of a signal that is applied to a light emittingelement is constant (CVCV), and in which current of a signal that isapplied to a light emitting element is constant (CVCC). In addition, asfor the driving method using video signals with constant current (CC),there are two kinds of methods in which voltage of a signal that isapplied to a light emitting element is constant (CCCV), and in whichcurrent of a signal that is applied to a light emitting element isconstant (CCCC).

In the light emitting device, a protective circuit for preventingelectrostatic breakdown (such as a protective diode) may be provided.

A protective layer 653 may be formed over the light emitting element 624of the pixel portion and the insulating layer 621. The protective layeris formed to prevent entry of moisture, oxygen, and the like into thelight emitting element 624 and the insulating layer 621. The protectivelayer 653 is preferably formed by a thin film forming method such as aplasma CVD method or a sputtering method, with an insulating materialsuch as silicon nitride, silicon oxide, silicon nitride oxide, siliconoxynitride, aluminum oxynitride, aluminum oxide, diamond like carbon(DLC), or carbon containing nitrogen (CN).

In this embodiment, since a source driver, a gate driver, and a TFT of apixel portion are formed over one substrate, a light emitting displaypanel can be thinned.

A space may be provided in a region 642 between the second substrate 640and the protective layer 653, which is filled with inert gas such asnitrogen gas. The entry of moisture or oxygen into the light emittingelement and the insulating layer can be suppressed.

The second substrate 640 can be provided with a colored layer. In thiscase, when a light emitting element capable of white light emission isprovided for each pixel and a colored layer for expressing R, G, or B isprovided separately, full-color display can be achieved. Moreover, whena light emitting element capable of blue light emission is provided foreach pixel and a color conversion layer is provided separately,full-color display can be achieved. Such an EL display module has highcolor purity of RGB and allows high-definition display. Moreover, alight emitting element expressing red, green, or blue light emission canbe formed for each pixel and a colored layer can also be used.

Further, in the case where light from the light emitting element 624 isemitted to the first substrate 600 side, a surface of the firstsubstrate 600 may be provided with a polarizing plate and a retardationplate. Meanwhile, in the case where light from the light emittingelement 624 is emitted to a second substrate 640 side, a surface of thesecond substrate 640 may be provided with a polarizing plate and aretardation plate. Furthermore, in the case where light from the lightemitting element 624 is emitted to both of the first substrate 600having flexibility side and the second substrate 640 having flexibilityside, surfaces of the first substrate 600 having flexibility and thesecond substrate 640 having flexibility may be provided with polarizingplates and retardation plates.

By connecting the light emitting display panel to an external circuitsuch as a power source circuit or a controller, a light emitting displaymodule can be formed.

Embodiment 5

Next, an example in which the liquid crystal display panel or the ELdisplay panel described above has an FPC or a driver IC mounted thereonis described. Here, a chip-like driver circuit formed by TFTs is calleda driver IC.

FIG. 27 shows an example of employing a COG method which is preferablefor a small size with a narrow frame (for example, 1.5 inch diagonal).

In FIG. 27, driver ICs 1011 are mounted onto a substrate 1010, and anFPC 1019 is mounted onto a terminal portion 1018 disposed at an end ofthe driver IC. A plurality of the driver ICs 1011 to be mounted arepreferably formed over a rectangular substrate having a side of 300 mmto 1000 mm or more in terms of improving productivity. That is to say, aplurality of circuit patterns each having a driver circuit portion andan input/output terminal as a unit may be formed over the substrate, andthe driver ICs may be obtained by dividing the substrate at the last.The driver IC may have a rectangular shape whose long side has a lengthof 15 to 80 mm and short side has a length of 1 to 6 mm in considerationof the length of the pixel portion on a side or the pixel pitch.

The superiority of the outside dimension of the driver IC to the IC chiplies in the length of the long side. When the driver IC has a long sideof 15 to 80 mm, the number of chips to be mounted is fewer than that inthe case of using the IC chip, thereby increasing the yield of theproduction. When the driver IC is formed over a glass substrate, theshape of the substrate used as a host material is not limited and theproductivity is not lowered. This is a great advantage in comparisonwith the case of obtaining IC chips from a circular silicon wafer.

Further, a TAB method is also applicable. In that case, a plurality oftapes may be attached and the driver ICs may be mounted to the tapes.Similarly to a COG method, a single driver IC may be mounted to a singletape. In such a case, a metal chip or the like for fixing the driver ICis preferably attached together in point of the mechanical strength.

A connection region 1017 between the pixel portion 1102 and the driverICs 1011 is provided so that the second conductive layer in the lightemitting element is in contact with the wiring of the lower layer.

Moreover, the sealing substrate 1014 is fixed to the substrate 1010 bythe sealing material 1015 surrounding the pixel portion 1012 and afilling material surrounded by the sealing material 1015.

The driver IC may be replaced by an IC chip formed by a Si chip.

Embodiment 6

Structures of semiconductor devices typified by RFID tags capable ofwireless data communication will be described in this embodiment, withreference to FIGS. 28A to 28C. As shown in FIG. 28A, a semiconductordevice 20 of this embodiment has a function of data communicationwithout contact, and includes a power supply circuit 11, a clockgeneration circuit 12, a data demodulation/modulation circuit 13, acontrol circuit 14 for controlling other circuits, an interface circuit15, a memory circuit 16, a bus 17, and an antenna 18.

Further, as shown in FIG. 28B, the semiconductor device 20 of thisembodiment has a function of data communication without contact, and mayinclude a central processing unit 21, in addition to the power supplycircuit 11, the clock generation circuit 12, the datademodulation/modulation circuit 13, the control circuit 14 forcontrolling other circuits, the interface circuit 15, the memory circuit16, the bus 17, and the antenna 18.

As shown in FIG. 28C, the semiconductor device 20 of this embodiment hasa function of data communication without contact, and may include adetecting portion 22 including a detecting element 23 and a detectioncontrol circuit 24, in addition to the power supply circuit 11, theclock generation circuit 12, the data demodulation/modulation circuit13, the control circuit 14 for controlling other circuits, the interfacecircuit 15, the memory circuit 16, the bus 17, the antenna 18, and thecentral processing unit 21.

When the semiconductor device of this embodiment includes the powersupply circuit 11, the clock generation circuit 12, the datademodulation/modulation circuit 13, the control circuit 14 forcontrolling other circuits, the interface circuit 15, the memory circuit16, the bus 17, the antenna 18, the central processing unit 21, thedetecting portion 22 including the detecting element 23 and thedetection control circuit 24, and the like, a small semiconductor devicehaving multifunction can be formed.

The power supply circuit 11 generates various kinds of power sources tobe supplied to various circuits inside of the semiconductor device 20based on alternating current signals inputted from the antenna 18. Inaddition, the power supply circuit 11 may include one or more of thesolar cells shown in Embodiment Modes 1 to 5. The clock generationcircuit 12 generates various clock signals to be supplied to variouscircuits inside of the semiconductor device 20 based on alternatingcurrent signals inputted from the antenna 18. The datademodulation/modulation circuit 13 has a function ofdemodulating/modulating data for communicating with a reader/writer 19.The control circuit 14 has a function of controlling the memory circuit16. The antenna 18 has a function of sending and receivingelectromagnetic waves or radio waves. The reader/writer 19 controlscommunication with the semiconductor device and processing of data ofcommunication. Note that the semiconductor device of the presentinvention is not limited to the above-described structures. For example,the semiconductor device may further include other elements such as alimiter circuit of power voltage and hardware only for processing codes.

The memory circuit 16 includes the memory element shown in the aboveembodiment mode. Since a memory element which includes a functionallayer having a layer including an organic compound can realizeminiaturization at the same time, reduction in thickness, and increasein capacitance, when the memory circuit 16 is provided using the memoryelement having the layer including the organic compound, a small andlightweight semiconductor device can be achieved.

The detecting portion 22 can detect temperature, pressure, flow rate,light, magnetism, sonic waves, acceleration, humidity, a componentcontained in a gas, a component contained in a fluid, and othercharacteristics by physical means or chemical means. The detectingportion 22 includes the detecting element 23 for detecting a physicalquantity or a chemical quantity and the detection control circuit 24,which converts a physical quantity or a chemical quantity detected bythe detecting element 23 into an appropriate signal such as anelectronic signal. The detecting element 23 can be formed by using anelement such as a resistor, a capacitive coupling element, aninductive-coupling element, a photovoltaic element, a photoelectricconversion element, a thermo-electromotive force element, a transistor,a thermistor, a diode, or the like, and one or more of the photoelectricconversion element, the diode, and the transistor shown in the aboveembodiment modes may be included in the detecting element 23. Note thata plurality of detecting portions 22 may be provided. In this case, aplurality of physical quantities or chemical quantities can be detectedat the same time.

Further, the physical quantities mentioned here indicate temperature,pressure, flow rate, light, magnetism, sonic waves, acceleration,humidity, and the like. The chemical quantities mentioned here indicatechemical substances and the like such as a gas component such as a gasand a component contained in a fluid such as an ion. In addition to theabove, the chemical quantities further include an organic compound likea certain biologic material contained in blood, sweat, urine, and thelike (e.g., a blood-sugar level contained in blood). In particular, inorder to detect a chemical quantity, a certain substance is inevitablydetected selectively, and therefore, a substance to be detected and asubstance which is selectively reacted are provided in advance in thedetecting element 23. For example, in the case of detecting a biologicmaterial, enzyme, an antibody molecule, a microbial cell, and the like,which are selectively reacted with the biologic material to be detectedby the detecting element 23, are preferably immobilized to a highmolecule and the like.

According to this embodiment, a semiconductor device which serves as anRFID tag can be formed. An application range of the RFID tag is wide.For example, the RFID tag can be, for example, used by being attached tobills, coins, securities, bearer bonds, certificates (such as a driver'slicense and a certificate of residence, see FIG. 29A), wrappingcontainers (such as a wrapping paper and a bottle, see FIG. 29C),recording media (such as DVD software and a video tape see FIG. 29B),vehicles (such as a bicycle, see FIG. 29D), belongings (such as a bagand eye glasses), foods, plants, animals, human bodies, clothes,livingwares, tags for commodities such as electronic appliances andbaggage (see FIGS. 29E and 29F), and the like. The electronic appliancesindicate a liquid crystal display device, an EL display device, atelevision device (also simply referred to as a television or atelevision receiver), a cellular phone, and the like.

Further, the semiconductor device 20 of this embodiment can be fixed togoods by mounting it on a printed substrate, or by attaching thesemiconductor device to a surface of the goods, embedding thesemiconductor device in the goods, or the like. For example, thesemiconductor device may be embedded in a paper of a book, or embeddedin an organic resin of a package that is formed using the organic resin.Since the semiconductor device 20 of this embodiment is small, thin, andlightweight, after fixing it to goods, design of the goods is notimpaired by the semiconductor device. By providing semiconductor devices20 of this embodiment to bills, coins, securities, bearer bonds,certificates, and the like, identification functions can be provided tothese things. By utilizing the identification functions, forgery ofthese things can be prevented. In addition, by providing thesemiconductor devices of this embodiment to wrapping containers,recording media, belongings, foods, clothes, livingwares, electronicappliances, and the like, an inspection system or the like can beimproved efficiently.

Embodiment 7

Next, an example of an electronic appliance equipped with asemiconductor device of the present invention will be described withreference to FIG. 30. A mobile phone is shown as an example here. Themobile phone includes casings 2700 and 2706, a panel 2701, a housing2702, a printed wiring board 2703, operation buttons 2704, and a buttery2705 (see FIG. 30). The panel 2701 is built in the housing 2702 and isfreely detachable. The housing 2702 is firmly attached to the printedwiring board 2703. The shape and the size of the housing 2702 arechanged as appropriate in accordance with an electronic appliance towhich the panel 2701 is built in. A plurality of semiconductor devicesthat are packaged is mounted over the printed wiring board 2703. Thesemiconductor device shown in the above embodiment modes and embodimentscan be used as one of the plurality of semiconductor devices 2710. Theplurality of semiconductor devices mounted over the printed wiring board2703 has any function of a controller, a central processing unit (CPU),a memory, a power supply circuit, an audio processing circuit, atransmitting/receiving circuit, and the like.

The panel 2701 is connected to the printed wiring board 2703 through aconnection film 2708. The panel 2701, the housing 2702, and the printedwiring board 2703 are housed inside of the casings 2700 and 2706 alongwith the operation buttons 2704 and the buttery 2705. A pixel region2709 included in the panel 2701 is arranged such that the pixel region2709 can be recognized by sight through an opening window. Asemiconductor device as shown in Embodiments 5 and 6 can be used as thepanel 2701.

As set forth above, the semiconductor device of the present invention issmall, thin, and lightweight, and therefore, a limited space inside ofthe casings 2700 and 2706 of the electronic appliance can be efficientlyutilized.

Note that the casings 2700 and 2706 only show example of an exteriorshape of the mobile phone, and electronic appliance to which thisembodiment is applied can be varied in accordance with its performanceand intended purpose.

Embodiment 8

Electronic appliances having the semiconductor devices shown in theembodiment modes and embodiments include a television device (alsoreferred to as a TV or a television receiving device, simply), a camerasuch as a digital camera or a digital video camera, a mobile telephonedevice (also referred to as a cellular phone device or a cellular phone,simply), a mobile information terminal such as a PDA, a mobile gamemachine, a monitor for a computer, a computer, an audio reproducingdevice such as a car audio component, an image reproducing deviceequipped with a recording medium, such as a home-use game machine, andthe like. The specific examples are described with reference to FIGS.32A to 32F.

A mobile information terminal shown in FIG. 32A includes a main body9201, a display portion 9202, and the like. By using the liquid crystaldisplay device or the light emitting display device shown in the aboveembodiment modes and embodiments for the display portion 9202, aninexpensive mobile information terminal which is thin, light weight, andconveniently portable can be provided.

A digital video camera shown in FIG. 32B includes a display portion9701, a display portion 9702, and the like. By using the liquid crystaldisplay device or the light emitting display device shown in the aboveembodiment modes and embodiments for the display portion 9701, aninexpensive digital video camera which is thin, light weight, andconveniently portable can be provided.

A mobile terminal shown in FIG. 32C includes a main body 9101, a displayportion 9102, and the like. By using the liquid crystal display deviceor the light emitting display device shown in the above embodiment modesand embodiments for the display portion 9102, an inexpensive mobileterminal which is thin, light weight, and conveniently portable can beprovided.

A mobile television device shown in FIG. 32D includes a main body 9301,a display portion 9302, and the like. By using the liquid crystaldisplay device or the light emitting display device shown in the aboveembodiment modes and embodiments for the display portion 9302, aninexpensive mobile television device which is thin, light weight, andconveniently portable can be provided. Such a television device can bewidely applied within the range of a small size which is mounted in amobile terminal such as a mobile phone to a middle size which isportable, and even applied to a large size (for example 40 inches orlarger).

A mobile computer shown in FIG. 32E includes a main body 9401, a displayportion 9402, and the like. By using the liquid crystal display deviceor the light emitting display device shown in the above embodiment modesand embodiments for the display portion 9402, an inexpensive mobilecomputer which is thin, light weight, and conveniently portable can beprovided.

A television device shown in FIG. 32F includes a main body 9501, adisplay portion 9502, and the like. By using the liquid crystal displaydevice or the light emitting display device shown in the aboveembodiment modes and embodiments for the display portion 9502, aninexpensive television device which is thin, light weight, andconveniently portable can be provided. Therefore, the television devicecan be used as a wall-hanging television or an electric signboard.

Embodiment 9

This embodiment shows an electric characteristic of an organicsemiconductor transistor included in a semiconductor device havingflexibility which is formed using the method shown in Embodiment Mode 1.

A manufacturing process of a semiconductor device of this embodiment isshown with reference to FIGS. 1A to 1E.

As shown in FIG. 1A, the photocatalytic layer 102 and the organiccompound layer 103 were sequentially formed over the substrate 101. Aglass substrate was used for the substrate 101. As the photocatalyticlayer 102, a composition including titanium oxide and butyl acetate(product name: Ti-03, made by Kojundo Chemical Laboratory. Co., Ltd) wasapplied onto the substrate 101 using a spin coater, and baking wasperformed at 600° C. for 15 minutes using a horizontal diffusionfurnace, so that a thin titanium oxide film was formed. As the organiccompound layer 103, the photocatalytic layer 102 was spin-coated with acomposition (product name: SUNEVER SE-5291, made by Nissan ChemicalIndustries, Ltd.), and then baking was performed at 180° C. for 30minutes using an oven, so that the organic compound layer 103 includingpolyimide was formed.

Next, the element forming layer 104 was formed over the organic compoundlayer 103. As the element forming layer, a layer having an organicsemiconductor transistor was formed. A method for forming the organicsemiconductor transistor is shown below. A composition including asilver particle (made by Harima Chemicals, INC.) was discharged at apredetermined position using an ink-jet method, and baking was performedat 180° C. for 60 minutes using an oven, so that a gate electrodeincluding silver was formed.

Next, a composition (product name: SUNEVER SE-5291, made by NissanChemical Industries, Ltd.) was applied using a spin coater, and thenbaking was performed at 180° C. for 30 minutes using an oven. Further, asolution in which 1 wt. % of polyvinyl cinnamate (made by AldrichChemical Company, Inc.) was dissolved in methyl ethyl ketone was appliedusing a spin coater, and baking was performed at 80° C. for 10 minutesusing a hot plate, so that a gate insulating film was formed.

Next, a composition including a silver particle (made by HarimaChemicals, INC.) was discharged at a predetermined position using anink-jet method, and baking was performed at 180° C. for 60 minutes usingan oven, so that a source electrode and a drain electrode which includesilver were formed.

Next, a semiconductor layer was formed by depositing purified pentaceneusing a metal mask, so that an organic semiconductor transistor wasformed.

Next, as shown in FIG. 1B, the substrate 101 was irradiated with thelight 105 from a metal halide lamp (160W) from a back surface (a glassside) for 15 minutes, so that the photocatalytic layer 102 wasactivated.

Next, a film with an adhesive agent was attached onto the organicsemiconductor transistor.

Next, as shown in FIG. 1C, an end portion of the film was lifted fromthe fixed substrate 101, and separation was performed at an interfacebetween the photocatalytic layer 102 and the organic compound layer 103,and then the element forming layer was transposed from the substrate tothe film. The size of the organic semiconductor transistor is asfollows: a channel length L/a channel width W=1600/165 μm. FIG. 33 showsa measurement result of an electric characteristic of the organicsemiconductor transistor which was transposed to the film when a drainvoltage Vd was set at −10 V. A solid line shows a drain current, anddotted lines show a gate current.

As set forth above, the element forming layer formed over the substratewas transposed to the film with the adhesive agent so that asemiconductor device having flexibility could be formed.

This application is based on Japanese Patent Application serial No.2006-058729 filed in Japan Patent Office on Mar. 3, 2006, the entirecontents of which are hereby incorporated by reference.

1. A method for manufacturing a semiconductor device, comprising:forming a photocatalytic layer and an organic compound layer in contactwith the photocatalytic layer over a substrate having a lighttransmitting property; forming an element forming layer over thesubstrate with the photocatalytic layer and the organic compound layerinterposed therebetween; and separating the element forming layer fromthe substrate by irradiating the photocatalytic layer with light.
 2. Amethod for manufacturing a semiconductor device, comprising: forming aphotocatalytic layer over a substrate having a light transmittingproperty; forming an organic compound layer in contact with thephotocatalytic layer; forming an element forming layer over the organiccompound layer; and separating the element forming layer from thesubstrate by irradiating the photocatalytic layer with light.
 3. Amethod for manufacturing a semiconductor device, comprising: forming anorganic compound layer over a substrate having a light transmittingproperty; forming a photocatalytic layer in contact with the organiccompound layer; forming an element forming layer over the photocatalyticlayer; and separating the element forming layer from the substrate byirradiating the photocatalytic layer with light through the substrate.4. A method for manufacturing a semiconductor device, comprising:forming a photocatalytic layer over a substrate having a lighttransmitting property; forming an organic compound layer having a lightshielding property in contact with the photocatalytic layer; forming anelement forming layer over the organic compound layer; and separatingthe element forming layer from the substrate by irradiating thephotocatalytic layer with light.
 5. The method for manufacturing asemiconductor device according to claim 1, wherein a substrate havingflexibility is attached to a surface of the organic compound layer afterthe element forming layer is separated from the substrate.
 6. The methodfor manufacturing a semiconductor device according to claim 2, wherein asubstrate having flexibility is attached to a surface of the organiccompound layer after the element forming layer is separated from thesubstrate.
 7. The method for manufacturing a semiconductor deviceaccording to claim 3, wherein a substrate having flexibility is attachedto a surface of the photocatalytic layer after the element forming layeris separated from the substrate.
 8. The method for manufacturing asemiconductor device according to claim 4, wherein a substrate havingflexibility is attached to a surface of the organic compound layer afterthe element forming layer is separated from the substrate.
 9. The methodfor manufacturing a semiconductor device according to claim 1, whereinseparation is performed at an interface between the photocatalytic layerand the organic compound layer, so that the element forming layer isseparated from the substrate.
 10. The method for manufacturing asemiconductor device according to claim 2, wherein separation isperformed at an interface between the photocatalytic layer and theorganic compound layer, so that the element forming layer is separatedfrom the substrate.
 11. The method for manufacturing a semiconductordevice according to claim 3, wherein separation is performed at aninterface between the photocatalytic layer and the organic compoundlayer, so that the element forming layer is separated from thesubstrate.
 12. The method for manufacturing a semiconductor deviceaccording to claim 4, wherein separation is performed at an interfacebetween the photocatalytic layer and the organic compound layer, so thatthe element forming layer is separated from the substrate.
 13. Themethod for manufacturing a semiconductor device according to claim 1,wherein the organic compound layer comprises an inorganic compoundparticle.
 14. The method for manufacturing a semiconductor deviceaccording to claim 2, wherein the organic compound layer comprises aninorganic compound particle.
 15. The method for manufacturing asemiconductor device according to claim 3, wherein the organic compoundlayer comprises an inorganic compound particle.
 16. The method formanufacturing a semiconductor device according to claim 4, wherein theorganic compound layer comprises an inorganic compound particle.
 17. Themethod for manufacturing a semiconductor device according to claim 1,wherein the organic compound layer has a light shielding property. 18.The method for manufacturing a semiconductor device according to claim2, wherein the organic compound layer has a light shielding property.19. The method for manufacturing a semiconductor device according toclaim 1, wherein the organic compound layer comprises an opticalabsorber or a light reflector.
 20. The method for manufacturing asemiconductor device according to claim 2, wherein the organic compoundlayer comprises an optical absorber or a light reflector.
 21. The methodfor manufacturing a semiconductor device according to claim 1, wherein awavelength of the light is a wavelength which activates thephotocatalytic layer.
 22. The method for manufacturing a semiconductordevice according to claim 2, wherein a wavelength of the light is awavelength which activates the photocatalytic layer.
 23. The method formanufacturing a semiconductor device according to claim 3, wherein awavelength of the light is a wavelength which activates thephotocatalytic layer.
 24. The method for manufacturing a semiconductordevice according to claim 4, wherein a wavelength of the light is awavelength which activates the photocatalytic layer.
 25. The method formanufacturing a semiconductor device according to claim 1, wherein theelement forming layer comprises at least one selected from groupconsisting of a thin film transistor, a diode, and a resistor.
 26. Themethod for manufacturing a semiconductor device according to claim 2,wherein the element forming layer comprises at least one selected fromgroup consisting of a thin film transistor, a diode, and a resistor. 27.The method for manufacturing a semiconductor device according to claim3, wherein the element forming layer comprises at least one selectedfrom group consisting of a thin film transistor, a diode, and aresistor.
 28. The method for manufacturing a semiconductor deviceaccording to claim 4, wherein the element forming layer comprises atleast one selected from group consisting of a thin film transistor, adiode, and a resistor.
 29. The method for manufacturing a semiconductordevice according to claim 1, wherein the element forming layer comprisesat least one selected from group consisting of a light emitting element,a liquid crystal element, and an electrophoresis element.
 30. The methodfor manufacturing a semiconductor device according to claim 2, whereinthe element forming layer comprises at least one selected from groupconsisting of a light emitting element, a liquid crystal element, and anelectrophoresis element.
 31. The method for manufacturing asemiconductor device according to claim 3, wherein the element forminglayer comprises at least one selected from group consisting of a lightemitting element, a liquid crystal element, and an electrophoresiselement.
 32. The method for manufacturing a semiconductor deviceaccording to claim 4, wherein the element forming layer comprises atleast one selected from group consisting of a light emitting element, aliquid crystal element, and an electrophoresis element.
 33. The methodfor manufacturing a semiconductor device according to claim 1, whereinthe semiconductor device functions as one of a light emitting device, aliquid crystal display device, an electrophoretic display device, awireless chip, a solar cell, and a sensor.
 34. The method formanufacturing a semiconductor device according to claim 2, wherein thesemiconductor device functions as one of a light emitting device, aliquid crystal display device, an electrophoretic display device, awireless chip, a solar cell, and a sensor.
 35. The method formanufacturing a semiconductor device according to claim 3, wherein thesemiconductor device functions as one of a light emitting device, aliquid crystal display device, an electrophoretic display device, awireless chip, a solar cell, and a sensor.
 36. The method formanufacturing a semiconductor device according to claim 4, wherein thesemiconductor device functions as one of a light emitting device, aliquid crystal display device, an electrophoretic display device, awireless chip, a solar cell, and a sensor.